Midterm & Beyond Flashcards
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
Two things that are true about 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 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 that help you see color and motion are found in the retina?
Macula and fovea are located there
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
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.