Anatomy Whole Term Review Flashcards
Which structure provides structure and nourishment to the retina?
choroid
Which structure(s) produces the aqueous humor?
ciliary bodies
Name three structures that provide protection for the eye.
bony orbit, conjunctiva, lacrimal system
What is the jelly-like substance, thick and viscous, that occupies the chamber in the posterior concavity of the eyeball?
vitreous humor
Which structure has the function of focusing light especially in near objects?
lens
The pupil is formed by which structure?
iris
Cones are responsible for sensing what two things?
color and fine detail
Which time on a clock describes the position of inferior rectus?
6 o’clock
What part of the skull encloses the eyes?
bony orbits
Which structure is the link between the visual system and the brain?
optic nerve
What time on a clock describes the position of the superior oblique rectus of the right eye?
2:00 (definitely not 7:00)
What structures are found in the anterior chamber of the visual system?
aqueous humor and cornea
What is the main structure involved in the bending of light?
cornea
If poor drainage of aqueous humor is an issue, which structure(s) could be be affected?
canal of Schlemm
What structure(s) produce tears?
lacrimal gland
What are the 5 categories of visual dysfunction?
visual acuity, field, binocularity, color perception, CVI
What are 3 things that cause all acuity problems?
refractive errors, diseases, syndromes
Which dysfunction is being described? “The sharpness of vision at a designated distance”
visual acuity
A normal eye generates how many diopters?
60
What is the term that means bending of light?
refraction
When an image is focused before it reaches the retina, because it is bending too much, that’s called…
myopia
What are the 4 refractive errors?
myopia, hyperopia, astigmatism, presbyopia
What is the term for unaligned eyes?
strabismus
What is the term for lack of symmetry in the curvature of the cornea?
astigmatism
What is the unit for measuring the amount of refraction?
diopters
Macular degeneration mainly causes which type of visual dysfunction?
visual field loss
Which term means binocular (both eyes) double vision?
diplopia
The area that can be seen by looking straight ahead
visual field
What unit is used to measure the visual field?
degrees
Is astigmatism related to where an image lands on the retina?
no- it’s related to the shape/curvature of the cornea
What is the main function of the bony orbit?
to protect the eyeballs
What is the thin layer that covers the eyes, attaches to eyelids, and protects the eyes?
conjunctiva
Which structure is the major refractor in the eye?
cornea
How much of the light bending in the eye does the cornea do?
90%
Where is the anterior of the eye? From the __ to the __
from the cornea to the iris
Which structure drains the occleus to keep pressure down?
Canal of Schlemm
What surrounds the lens, keeps it in place, is attached to ciliary bodies, and are most involved in the process of focusing?
Zonules of Zinn
What area in the retina provides sharp vision with the greatest detail?
macula
Which structure is the sentry/file station, and sorts information?
geniculate bodies
At what time on a clok face is the medial rectus positioned? (looking at right eye)
3:00, by the nose
At what time on a clock face is the lateral rectus positioned? (looking at right eye)
9:00, by the temple
At what time on a clock face is the superior rectus positioned?
12:00
At what time on a clock face is the inferior rectus positioned?
6:00
Which muscle moves the eye UP?
superior rectus
Which muscle moves the eye DOWN?
inferior rectus
Which muscle moves the eye IN?
medial rectus
Which muscle moves the eye OUT?
lateral rectus
What should a child be wearing during an eye exam?
Their best glasses or contacts, so it can be determined how well the child can see with correction.
Part of retina made mostly of cones, center of macula, provides sharp vision
fovea
Colored part of the eye, controls the amount of light that enters the eye, helps sharpen focus
iris
If problems in this part of the eye, a person might experience photophobia, too much light, glare, loss of acuity, pain, too little light
iris
Which structure protects and cares for the eye through controlling tears?
lacrimal system
Structure that changes shape/thickness to add bending power for closer viewing (accommodation)
lens
Where cataracts form
lens
Part of the retina with the highest concentration of cones, used for reading very small print, central visual field is here
macula
What is ARMD?
age related macular degeneration
Where information from both eyes cross to create a complete visual picture. Nerves from each eye come together and are split so information from both eyes is shared with both parts of the brain
optic chiasm
Where optic nerve and retinal blood vessels enter and optic nerve attaches from the brain, where the blindspot is in each eye
optic disc
Bundle of nerves that carry information from the retina to the brain
optic nerve
What is the most common eye condition related to optic nerve damage caused by abnormally high pressure in the eye
glaucoma
Which structure is in the corner of the eye, pink skin that covers gland
coruncula
What structures make up the uveal tract?
choriod, ciliary body, iris
What does the ciliary body produce?
aqueous humor
Perceives fine details, color, color contrast, clear vision, and objects positioned in the central portion of vision
cones
How many cones and rods do we have?
6 million cones, 120 million rods
What is concentrated in the fovea, which is the center of the macula?
cones
Crystalline is another name for which part of the eye?
lens
Where does the optic tract start? Where does it go next?
starts at the optic chiasm and goes to the geniculate bodies, then onto the brain
Where is the posterior chamber? Behind the __ and in front of the __.
behind the iris and in front of the lens
Hole in the top and bottom lid to collect tears
punctum
Opening of the iris, hole that expands and contracts as the iris changes shape
pupil
Nerve layer lining 2/3 of the back of the eye, connected to our brain
retina
Disorder that affect babies born too early, before blood vessels have developed to the edge of retina, so abnormal blood vessels develop which are fragile and weak, and as they scar they shrink, pull on the retina and detach it
ROP - retinopathy of prematurity
Perceive movement and objects in low light, as well as objects located in the edges of vision, no color, found in greater number around the edges of the retina
rods
Congenital eye disorder that first affects the rods and leads to decreased night vision
RP - retinitis pigmentosa
The white part of the eye, tough outer wall that with the cornea forms the external coat of the eye, also forms protective sheath around the optic nerve.
sclera
Fibers that connect the ciliary body of the eye with the lens, holding it in place
suspensory ligaments
Dots along the base of bottom lid that produce oils and prevent evaporation and prevent tear spillage onto the cheek making closed lids airtight
tarsal glands
Serve to clean and lubricate the eyes in response to irritation, produced by the lacrimal gland
tears
Layer of tissue between the outer and inner layers of the eye
uveal tract
AKA Occipital lobe
visual cortex
AKA Visual cortex
occipital lobe
Which part of the brain is involved with spatial organization of a scene, shapes, brightness and shading?
primary visual cortex
Which part of the brain interprets patterns?
secondary visual cortex
Supports the retina against the choroids, provides structure and shape of the eye, fills up central cavity
vitreous humor
What are the 6 refractive structures, in order?
TCCALV - tears, conjunctiva, cornea, aqueous, lens, vitreous
Eye condition caused by high pressure in the eye
glaucoma
What two structures make up the outer layer of the eye, and in what proportions?
sclera is 5/6 and cornea is 1/6
Which system of structures provides light absorption? What three structures are included?
uveal tract - iris, choroid, ciliary bodies
Which part of the brain is the center for visual learning and recognition by sight?
temporal lobes
Which part of the brain is the limbic sector and guides visual attention and is involved with emotional responses?
midbrain
Which cranial nerve is responsible for most eye movement, pupil, and lid function?
3rd cranial nerve
Which cranial nerve works the superior oblique and may cause double vision, manifested by a head tilt?
4th cranial nerve
Which cranial nerve is responsible for the lateral rectus?
6th cranial nerve
What is measured by determining the smallest object or line seen clearly at a set distance?
visual acuity
What does 20/30 vision mean?
you can see at 20 feet what a person with “normal vision” can see at 30 feet - less acuity than the average person (worse vision) - the higher the bottom number, the less visual acuity a person has
On an eye prescription, what does OD mean?
right eye
On an eye prescription, what does OS mean?
left eye
On an eye prescription, what does OU mean?
both eyes
On an eye prescription, what does + mean?
farsighted, so need to add (+) more bend
On an eye prescription, what does - mean?
nearsighted, so need to decrease (-) bend
On an eye prescription, what does AXIS refer to?
astigmatism
On on eye prescription, what is the range for sphere?
1 - 9 diopters
What is the benchmark for legal blindness?
20/200 with correction, with both eyes
How many diopters are generated by an eye?
60
Of the 60 diopters per eye, how many are from the cornea?
40 diopters from the cornea
Which refractive error requires a concave lens?
myopia
Which refractive error requires a convex lens?
hyperopia
Which refractive error is caused by a loss of accommodation, usually in 40+ yrs olds?
presbyopia
Which term refers to the ability to adjust the focus on an object being viewed?
accommodation
Area of space above, below, left and right when visible while looking straight ahead
visual field
Each eye sees how many degrees horizontally?
160 degrees
How many degrees of overlap are there between the two eyes when working together?
60 degrees
Blind spots within the visual field
scotomas
Any condition affecting the retina will affect which visual dysfunction?
visual field
What term describes the hemisphere you can’t see?
hemianopsia
Visual field losses can be described as __ or __
lateral or central
Using two eyes together to form a three-dimensional object
stereopsis
Ability to see the world in 3-d and perceive distance using cues from one or both eyes
depth perception
Double vision
diplopia
Double vision in just one eye
monocular diplopia
When the brain fails to process input from one eye and over time favors one eye over the other (lazy eye)
amblyopia
When an eye turns in, toward the nose
esotropia
When an eye turns out, toward the temple
exotropia
When an eye turns downward
hypotropia
When an eye turns upward
hypertropia
Involuntary movement of the eye
nystagmus
Which visual dysfunction is primarily inherited?
color perception
Loss of cone receptors which results in total loss of color vision
achromatopsia
School activities that will provide challenge for those with color perception problems
maps, charts, graphs, color coding
What is the current leading cause of VI in children?
CVI
What is the fastest growing visual impairment diagnosis?
CVI
Brain problem rather than an eye problem - eyes are physically fine
CVI
Absence of visually guided reach (look, look away, touch) is related to which visual dysfunction?
CVI
What are the critical windows when children have the most pronounced visual plasticity and opportunity for vision rehabilitation?
0-6 months and 3 years
What are some CVI strategies?
more response time, routines, consistency, predictability, focus on daily living skills, simple tasks and goals, visual experiences scheduled for optimal times
What is visual acuity at birth?
20/400
In a baby, when is 20/20 vision usually achieved by?
2 years
What term will doctors use to indicate that a child is not seeing well yet?
delayed visual maturation
Functional implication of loss of acuity
severe problem everywhere and all the time
Functional implication of loss of accommodation
can’t focus on close objects, reading, games, classwork
Functional implication of loss of stereopsis
lack of binocular vision, problems with PE, movement, stairs, driving
Functional implication of diplopia
double vision, trouble reading, writing, PE
Functional implication of glare
excess light entering the eye and decreases visual acuity, problems outside, fluorescent light, whiteboards
Functional implication of problems adapting to changes in light levels
cannot adapt to environmental changes in light, photophobia is when even normal light hurts eyes, other conditions may require more light to improve function
Which conditions may require more light to improve functional vision?
albinism, RP, stargards, macular degeneration
Functional implication of problems with color discrimination
cannot interpret some or all hues of color, maps, charts, getting dressed
Functional implication of inability to maintain visual acuity
fatigue, ocular mobility challenges limits ability to use vision, afternoon/homework is an issue because students’ eyes are done
Functional implication of difficulty obtaining or maintaining fixation on an object
problem going through lunch line, grabbing small items, placing on proper section of tray
Functional implication of inability to obtain a complete view of visual field
blind spots (scotoma), problems with sports, crossing the street
Functional implication of ambulation difficulties
problem with unfamiliar areas
Functional implication of inability to locate objects in the visual field or locate changes in terrain or levels
bleachers, pep rallies, football games, marching band
Functional implication of difficulty in recognizing, using, or storing visual information
challenges with spatial or pattern recognition or memory, trouble with color, contrast, complexity
What 5 types of needs should be addressed for students with VI?
social skills, self-advocacy, self help, recreation and leisure, interpersonal skills
On your prescription, what does ADD mean?
bifocals, diopters added to the lower part of the lens
Nickname for presbyopia
long arm syndrome
Person A is extremely nearsighted. Which might appear on the prescription? +1 +8 -1 -8
-8
What time describes the position of the inferior rectus?
6:00
Term for binocular double vision
diplopia
Unit for refraction
diopters
Four refractive errors
Myopia, hyperopia, astigmatism, presbyopia
Macular degeneration is associated with which visual dysfunction?
Visual field loss
Area seen looking straight ahead, measured in degrees
Visual field
Unaligned eyes
strabismus
Lack of symmetry in curvature of cornea
astigmatism
What are the pairs of ocular muscles?
Superior and inferior recti, lateral and medial recti, superior and inferior obliques
At age 40, which visual dysfunction are adults likely to develop?
Presbyopia
What are the three causes of acuity problems?
Refractive errors, disease, syndromes
If the eye attempts to focus the image before the retina, there is too much bending, so what type of lens is needed to diverge rays before they reach the cornea?
Concave
What is the path of light through the refractive structures of the eye?
Tears, conjunctiva, cornea, lens, aqueous, vitreous
What supports and nourishes the eye?
Choroid
What three structures provide protection for the eye?
Bony orbit, conjunctiva, and lacrimal system
What structure helps to maintain pressure in the anterior and posterior chambers of the normal eye?
Canal of Schlemm
What are the differences in the functions of cones and rods?
Cones perceive fine details, color, and central vision. Rods perceive movement, objects in low light, and peripheral
Two things that are true about the optic tract?
Starts at the chiasm and goes to the geniculate bodies. Carries information from both the left and right eye to each side of the brain
Similarities and differences between hyperopia and presbyopia?
Both are refractive errors. Both are related to difficulties seeing things up close. Hyperiopia would have a convex lens prescription, while presbyopia would have a bifocal lens prescription. Hyperopia is caused by the eye being too short or lack of bend in the cornea, while presbyopia is caused by the lens losing its ability to accommodate and focus on items up close.
At what time is superior oblique rectus of the right eye?
About 2:00. Definitely not 7:00.
Sharpness of vision at designated distance
visual acuity
A normal eye generates how many diopters?
60
List 9 structures that will encounter image information in order
Tears, lens, vitreous, retina, optic disc, optic chiasm, optic tract, lateral geniculate nucleus, visual cortex
What visual dysfunction is when the image is focused before it reaches the retina?
Myopia
Looking ahead, an object is coming into view from the right. You see the object first with which, or both eyes?
Right eye
Where does the greatest portion of processing of visual information take place?
Visual cortex
Which two structures (not rods and cones…) that help you see color and motion are found in the retina?
Macula (centered of the retina and responsible for sharp, clear, straight ahead vision) and fovea (depression at center of macula that provides greatest visual acuity)
What produces aqueous humor?
Ciliary bodies
Three true things about vitreous humor?
Ideal material for light to travel through, provide structure for the eye, support the retina (it is NOT produced throughout your life and it does NOT nourish the cornea)
Two facts about the fovea?
Part of retina, composed mostly of cones
Doctor says that bending power of the eye is 60 diopters. What should you expect?
No problem with acuity.
What is true about the aqueous humor?
Nourishes the conjunctiva and cornea in front of the eye, helps bend light
What is true about the vitreous humor?
Supports the shape of eye and lens, helps bend light
Where is the point that visual information splits into two?
Optic chiasm
Which structure is most involved in focusing in the eye?
Zonules of Zinn
The area of the retina with the highest concentration of cones
Macula
Jelly like structure, thick and viscous, occupies chamber in the posterior cavity of the eyeball
Vitreous humor
The pupil is formed by which part of the eye?
Iris
Where in the retina are rod cells found in greater number, center or peripheral?
Peripheral/outer edges
Cone cells are responsible for color and…
fine detail
The part of the retina that is used to read very fine print…
macula
Function of rods
perceive movement, see objects in low light, objects located in edges of vision
How would vision be impacted if the iris did not function properly?
Too much/too little light in eye
Which of the 5 areas of vision would be affected if the retina had problems?
Visual field
Myopia vs. hyperopia, including probable causes
Myopia - eye is too long or cornea too curved, object is in view before retina, needs less bend so negative prescription, concave lens Hyperopia - eye is too short or cornea too flat, object is in view behind retina, needs more bend so positive prescription, convex lens
Covering of thin tissue stretched over the top of the eye and up into eyelids
Conjunctiva
What does a +3 prescription mean
Farsighted
Information from the retina travels along a “cable” to the optic chiasm, cable is called the…
Optic nerve
Common visual condition that affects information processing?
CVI
Sensory relay station
Geniculate bodies
Visual field losses can be related to problems with which three situations?
Loss of cornea, optic nerve issues, retina issues (but not lens removal)
If you had severe problems with the macula, you’d expect problems with…
Central visual field
Convex lens corrects…
Hyperopia
How much overlap is there between the visual fields of the left and right eyes?
60 degrees
Appearance of eyes
During an examination of the appearance of the eyes, the doctor would inspect the eyelids and the area of the eye between the eyelids. The conjunctiva and the sclera are inspected by retracting the upper and lower eyelids and shining a light onto the eye while the patient looks up.
Blink to threat
Blink to threat a method used by doctors to test visual processing. In response to sudden finger gestures near the eyes, it is a normal reflex to blink. If the patient does not blink, it can be an indicator that there is difficulty with visual processing.
Counts fingers
CF means counts fingers. For people with low visual acuity, they are asked to count fingers at a certain distance. A report of “CF 3” would indicate that the patient could count the doctor’s fingers at a distance of three feet.
Convergence
Convergence is the ability to turn two eyes inward toward each other to look at a close object.
CSM
CSM is a method of testing visual acuity in preverbal or nonverbal children. C stands for centrality and refers to the location of the corneal light reflex as the patient looks at the doctor’s light with the other eye covered. Normally the light reflex should be located near the center of the cornea. S refers to the steadiness of the patient’s fixation on the examiner’s light. M refers to the patient’s ability to maintain alignment.
ECC
ECC stands for the Expanded Core Curriculum. The ECC is used to define concepts and skills requiring specialized instruction for students who are blind or visually impaired in order to compensate for their inability to learn by visual observation of others, either to be able to access the general curriculum or meet needs specific to the child’s disability. There are 9 areas: assistive technology, career education, compensatory skills, independent living skills, orientation and mobility, recreation & leisure, self determination, sensory efficiency, and social interaction skills.
Eye contact
Eye contact is aligning pupils with another person, one of the most important forms of nonverbal communication. Eye contact is important for recognizing non-verbal and social cues, which puts students with visual impairments at a disadvantage socially.
Eye preference
The eyes should be used simultaneously. One eye should not be favored over another, which may be indicated by head turning or tilting, or holding objects to one side to look at them.
Fixation
Fixation is the ability to accurately aim the eyes at a particular spot.
FVE
FVE stands for functional vision evaluation. A functional vision evaluation is an evaluation of visual abilities as used in functional tasks, such as reading, daily living, vocational pursuits, and educational programming. An FVE is usually conducted at the person’s school, home or work environment. Also known as functional vision assessment.
HHSC
HHSC stands for the Health and Human Services Commission. This organization provides guidance and support for families with students with disabilities. The areas of support are: diagnosis/health care, insurance/finance, family support, education/schools, transition to adulthood, and services/groups/events.
HM
HM refers to hand motion, or the ability of a person to perceive whether or not a hand is moved directly in front of the eyes. This test of visual acuity is given if the patient has difficulty with the counting fingers test. The letters HM and the distance would indicate how far away the patient could see the moving hand, though often HM is reported without a testing distance since most of the testing is done within one foot of the patient’s eyes.
ID
ID stands for intellectual disability. People with intellectual disabilities such as Down’s syndrome, cerebral palsy, Rubella syndrome, and Fragile X syndrome are at a higher risk for experiencing sight problems.
IOL
-IOL refers to an Intraocular lens, which is a tiny, artificial lens transplanted into the eye as treatment for cataracts or myopia.
IOP
IOP is the intraocular pressure within the eye, measured using the tonometer, which sends a puff of air into the eye. IOP is important in the evaluation of patients at risk of or suspected of glaucoma. Intraocular pressure is determined by the production and drainage of the aqueous humor.
LID
LID is the acronym for low incidence disabilities, which include visual impairments, hearing loss, deaf-blindness, or cognitive impairment. It includes any conditions that require specialized instruction for a child to be able to benefit from their education.
LMA
- LMA stands for learning media assessment. The LMA determines what format the student will use to read and write. It may include braille, large print, audio, digital text, or a combination of those. Assistive technology and low vision devices could also be used. The LMA provides information about the accessible educational materials students will need for their classes. A key purpose of the LMA is to determine whether or not the student needs braille.
Localization
Localization is having an awareness of the location of an object of interest in the environment from visual, auditory, or kinesthetic cues so that a fixation can be directed toward it.
LP
Light perception (LP) is the ability to perceive the presence or absence of light. It could mean knowing whether the room is dark or light, or being able to move toward a lighted lamp.
MDVI
MDVI stands for multiple disabilities and visual impairment. People with MDVI have vision impairment as well as one or more additional disabilities.
Muscle balance
The two eyes are meant to move together and in the same position. If they do not move at the same speed or in the same direction, then the brain receives different signals that cannot be merged into one image, resulting in double vision. Muscle balance can be tested with a corneal light test, the cover test, or looking at a person’s tracking ability.
NLP
NLP is the acronym for “no light perception.” Total blindness is recorded as NLP, which refers to no light or form perception.
O & M
O & M stands for Orientation and Mobility, which refers to travel and movement. Students should be oriented in their surroundings and able to move around as independently and safely as possible. Students learn about themselves and their environments, including home, school, and the community. O & M lessons can include basic body image, spatial relationship, purposeful movement, cane usage, travel in community, and public transportation. The goal of O & M is for students to be as independent as possible.
OD
On a glasses prescription, OD refers to the right eye. OD is the abbreviation for a latin term, oculus dextrus.
OS
On a glasses prescription, OS refers to the left eye. OS is the abbreviation for a latin term, oculus sinister.
OU
On a glasses prescription, OU refers to the visual acuity with both eyes together. OU is the abbreviation for a latin term, oculus uterque.
Pupillary response
Pupillary response is the constriction of the pupil in response to light. There is also consensual pupillary response, when the other eye also constricts, but usually to a lesser extent.
ROP
ROP stands for Retinopathy of Prematurity. ROP is an eye disease that occurs in premature babies. When children are born early, the blood vessels to the retina haven’t finished growing. They stop growing for a time, then start growing abnormally. These new vessels are not strong and they leak, bleed, or cause scarring. As the scars shrink they may detach the retina from the back of the eye, which could result in blindness. Functional vision in people with ROP can range from near normal to total blindness.
Scanning
Scanning is making a series of fixations in order to inspect a large area visually.
Shifting of gaze
Shifting of gaze is changing fixation to a new object of interest.
Snellen Chart
A Snellen Chart is an eye chart used to measure visual acuity. The smallest row that can be read determines a person’s visual acuity in each eye.
TBI
A TBI is a traumatic brain injury, which is a sudden injury that causes damage to the brain. TBI can affect vision by damaging the parts of the brain involved in visual processing and/or perception. The most common eye issues associated with TBI are blurred vision, double vision, and decreased peripheral vision.
Tracking
Tracking is the ability to quickly and accurately fixate on an object, visually follow a moving object, and to efficiently move the eyes from point to point, as is done while reading.
TSBVI
TSVBI is the acronym for Texas School for the Blind and Visually Impaired, located in Austin, Texas. TSVBI has some students who attend on-site. But the institution serves 11,000 students throughout Texas by providing courses, consultations, publications, and training for students and staff working.
UCUSUM
UCUSUM stands for “uncentral unsteady unmaintained.” One eye is covered, and the doctor notes if the fixation is central or uncentral, if the fixation remains steady on an object while it is held still and slowly moved, and if the patient is able maintain fixation with the viewing eye when the other eye is uncovered. UCUSUM would mean that the fixation was uncentral, unsteady, and unmaintained.
Visual field
Visual field is the area that one can see above, below, left, and right, when facing directly ahead. It is measured in degrees.
In determining eligibility for low vision services, what must the eye report from an optometrist or ophthalmologist include?
Must include vision loss in exact measures of visual field and corrected visual acuity, at a distance and close range, in each eye; or best estimates of visual loss if exact measures cannot be obtained
For a student already receiving special education services, what must be in place before a FVE is requested?
an eye report less than one year old and corrective lenses, if indicated by report
For a student not receiving special education services, why is it recommended that the eye report be received before requesting a FVE?
timeline constraints and treatment recommendations
What 2 documents are needed for a student to qualify for VI services?
eye report, FVE/LMA
What is a FVE?
An evaluation procedure used to determine how an individual uses vision in everyday life tasks
Who can perform an FVE?
TVI or O & M
How is an FVE conducted? (4)
Systematically, using a protocol, on multiple days, in multiple environments
What is in a Learning Media Assessment? (3)
efficiency with which a student gathers information from sensory channels, types of general learning media a student uses and instructional methods, literacy media the student will use for reading and writing
Who can perform a LMA?
Only a TVI
What is the ECC? (Expanded Core Curriculum)
Concepts and skills that require specialized instruction to compensate for decreased opportunities to learn by observing others
What are the 9 components of the ECC?
A- Assistive Technology
C - Career Exploration
C - Compensatory or Functional Skills
R - Recreation and Leisure
O - Orientation and Mobility
S - Social Interaction Skills
S - Self-Determination
S - Sensory Efficiency
I - Independent Living Skills
Who can perform the ECC assessment?
TVI or O & M
FVE/LMA process (8)
- Referral
- Eye report received
- Record reviewed
- Interviews conducted
- Observations conducted (multiple days/environments)
- Protocol completed
- Report written
- ARD/IEP meeting held
If glasses held to print bring the print closer, it means they are …
concave/nearsighted
If glasses held to print make the print smaller, it means they are…
convex/farsighted
Distance or near? Telescope/Monocular
Distance
Uses for Telescopes/Monoculars
Reading from blackboard from 10+ feet, looking at objects you can’t get close to, driving, watching sporting events/concerts
Advantages of Telescopes/Monoculars
Makes distant objects appear closer, can be used inside or outside, portable, can be used in reverse as a field expander
Disadvantages of Telescopes/Monoculars
Requires good contrast, reduces visual field, copying from board is difficult, can be expensive, requires extensive training
Distance or Near? Hand Magnifiers
Near
Uses for Hand Magnifiers
reading signs, labels, ID money, inspect objects, quick spot reading
Advantages of Hand Magnifiers
easy to carry, portable, available from low to high power, cheap to make or buy, can be used in any position or angle, allows light onto print or objects
Disadvantages of Hand Magnifiers
difficult to keep appropriate distance, one hand occupied, difficult to hold steady (tremor)
Uses for Stand Magnifiers
Reading from a book or newspaper, looking at a picture or diagram
Advantages of Stand Magnifiers
Has a fixed distance for ease of movement, easy to use, available from low to high magnification, some have built in lights
Disadvantages of Stand Magnifiers
Keeps one hand occupied, not useful for writing, poor posture, causes fatigue
Distance or Near? Spectacle Microscopes (rare!)
Near
Uses for Spectacle Microscopes
reading any material, writing, looking at objects from a close range
Advantages of Spectacle Microscopes
range of magnification, both hands free, readily available, once used efficiently can be used for long periods, can be built into traditional eyeglass frames
Disadvantages of Spectacle Microscopes
exact reading distance is important, short reading distance with high powered lenses, more fragile than magnifiers (scratching, breaking), good lighting is needed, often needs to be paired with a reading stand to bring material close
Distance or Near? Video Magnifiers
Both (new technology!)
Uses for Video Magnifiers
Read mail, books, newspapers, write letters, pay bills, do craft work, exploring
Advantages of Video Magnifiers
Color or black and white, magnificiation up to 60 times, reversible print/background, can be integrated with computers, great for longer reading tasks, now portable options
Disadvantages of Video Magnifiers
Cost!
Glare - which dysfunction is related?
photophobia/light sensitivity can be a severe problem
What does wavelength have to do with glare?
Shorter wavelength, high-energy part of the visible spectrum dominates daylight and contributes to glare
FVE & Glare…
Consider both inside and outside glare problems
How do filters help with glare control?
Filters reduce glare and increase contrast, reduce chromatic aberration, light scattering, and fluorescence
Besides filters, how else can glare be controlled?
Hats/visors
How important is it to consider lighting?
Very - lighting is often the most helpful low vision aid, proper lighting and positioning can be more important than magnification!
How much more illumination do low vision patients require?
5 times more illumination
What are lighting considerations?
Positioning - direct light on reading material, reduce shadowing. Minimize Glare - do not face window, close blinds. Night Lights - carry a flashlight.
What are some non-optical aids for writing?
Signature, letter, envelope guides, bold black pens, paper with thick black lines
What are some non-optical aids for the computer?
Screen enlarging software, large print keyboards, large print labels
What is meant by “One is not enough”?
No single vision device will serve all visual needs, mosy people require a combination of devices for different tasks.
How can field defects be treated?
Prism, reverse telescopes, class placement (preferential seating), guidance (driving, vocation), scanning skills, cane
Prism
Attach to glasses, pull in items from visual field loss, puts image in center of lens, Image displacement, must have good central acuity, patient must be high functioning, reduction of vision
Reverse telescopes
minification of images, need good scanning skills, distorted perception (peep hole), not for use while moving
Conditions that cause peripheral vision loss
Retina detachment, Retinitis Pigmentosa, Glaucoma, Head injuries/brain tumor/stroke, ROP, Colobomas, Retinoblastoma, optic nerve hypoplasia
Conditions that cause central vision loss
Macular Degeneration, Stargardt’s, CVI, diabetic retinopathy, nystagmus
What structure provides nourishment and support to the retina?
Choroid
About how many diopters does the normal eye generate?
60
What if the prescription says +2?
Slightly farsighted (hyperopic)
What are diopters?
Unit of measurement of refraction
Albinism is associated with nstagmus and astigmatism. What type of dysfunction is related to nstagmus?
Low acuity
What is the cable called that travels from the retina to the optic chiasm?
Optic nerve
How would you know if someone was prescribed a bifocal?
The prescription would have an ADD power.
Term that allows eyes to sees depth perception?
stereopsis
What does the lens do?
Focuses light for near objects, accommodation.
Amblyopia…
What doesn’t cause it, and what might cause it?
Not caused by stereopsis or trauma to the eye
Could be caused by muscle imbalance or acuity loss
Visual field information - each eye has about 90 degrees of field - if you have retinal issues, would you have visual field loss?
Yes
Full visual field range
160 degrees
At what point (acuity) is a person considered legally blind?
20/200
What is eccentric viewing?
Looking away from the visual target to see it better, using peripheral vision
What kind of diagnosis of vision loss would a head injury cause?
Cortical visual impairment
Are visual acuity and visual field stable or do they flucuate with a CVI?
fluctuate
What is the instrument used to assessed the health of the vitreous or the retina?
opthalmascope
If the eyes are not able to distinguish object details and shape, we say they have problems with…
acuity
If you can’t see fine detail well, and have problems reading, what kind of field loss do you have?
central
Would someone who has cataracts have possible acuity loss?
YES!
Would someone with cataracts possibly have field loss?
Yes
Would someone with cataracts possibly have clouding on their lens?
Yes
If a person is not able to distinguish between colors that are similar, what is it called?
Contrast sensitivity
Hemanopsia - true or false?
Considered to be a field loss
Only top and bottom field loss
TRUE - means half a field loss
FALSE - can be left or right field loss
CVI - true or false
Can be caused by trauma to the brain
Visual functioning can vary from day to day
Those with milder degrees will develop central vision only
Can occur in children born prematurely
TRUE
TRUE
FALSE
TRUE
Big black spots on the duck pond picture - what is the condition called?
Scotomas
If the brain can’t process visual information sent to it from the eye through the optic nerve, does that mean there is some damage to the brain?
Does it mean that they have processing problems?
Yes
Yes
Can vision loss result in developmental delays in all areas?
Yes
