Basic Medical/ Vision Terms Flashcards
Accommodation
The ability of the eye to focus from distance to near
Ametropia
Condition in which, when accommodation is relaxed, parallel light rays entering the eye do not focus on the retina. (Ex: myopia, hyperopia and astigmatism).
Also a non-specific term that means the patient has a refractive condition.
Aphakia
Absence Of Crystalline Lens
When a cataract progresses to the degree that it interferes with vision, the crystalline lens can be surgically removed.
Aqueous Humor
Clear fluid produced in the ciliary processes and fills the space from the posterior cornea to the anterior vitreous; maintains the intraocular pressure; nourishes the cornea, iris, and lens
Asepsis
Practice to reduce/ eliminate contaminants (such as bacteria, viruses, fungi and parasites) from entering the operative field in surgery or medicine to prevent infection
Astigmatism
Image focused at two points, cornea longer in one meridian than another
• “football-shaped” cornea
• Different power of lens to correct each meridian
corrected by use of cylindrical eyeglasses or contact lenses (spherical or toric)
Base Curve
Measurement of the back curvature of a lens
Bifocal
Lens that provides both distance and near correction.
Binocular Vision
Simultaneous use of both eyes.
The ability to maintain visual focus on an object with both eyes creating a single visual image.
Biomicroscope
Instrument used for observing a fit of contact lenses, checking for foreign bodies in the eye and looking at all parts of the front of the eye including eyes, lids and lashes.
Bulbar
Conjunctiva covering the eyeball that protects the sclera (white part of eye).
Cataract
When crystalline lens gets hard or cloudy with age.
Is a clouding of the eye’s lens and is the leading cause of blindness.
Chief Complaint
Patient’s reason for the office visit
Concave Lenses
Lens that is thinner in the center and thicker at the edges; parallel light passing through this type of lens is diverged, or refracted, away from the midline. Also known as a minus lens
Confrontation Fields
Technique used to screen for visual field defects using the fingers of the examiner
Patient looks directly at examiners eye or nose and testing each quadrant in the patient’s visual field by having them count the number of fingers the examiner are showing.
Convex Lenses
A lens that is thicker in the center and thinner at the edges; parallel light rays passing through this type of lens are refracted by each surface to converge toward the midline behind the lens. Also known as a plus lens
Diopter
Unit of refractive power; abbreviated with the letter “D”. Measure of how much an ophthalmic lens refracts or bends light that can be used to determine its power. (Ex: a one-diopter lens will focus light at one meter.)
Disinfection
To destroy harmful bacteria and viruses.
Edema
Swelling of tissues due to fluid influx
Emmetropia
Image will focus on retina when accommodation is relaxed. No lenses needed 20/20 or “perfect vision”
Fluorescein/ Fluorescein Sodium
Most commonly used ophthalmic dye which is available in liquid form or impregnated on dry, paper filter strips.
Dye used topically to evaluate corneal integrity and intravenously to evaluate blood vessel integrity. Tear film quality is best observed when a fluorescein drop is used.
Fovea/ Fovea Centralis
Central (1.5 mm) area of the macula; responsible for the sharpest vision, fine discriminations and high visual acuity. The area of the macula that is used for daytime and color vision also the area of highest concentration of cone cells and no blood vessels.
Fundus
Interior portion of eyeball that can be seen on ophthalmoscopy or photography. Includes the retina and optic disc.
Glaucoma
Intraocular pressure disease. Group of eye conditions that damage the optic nerve.
A group of diseases that can damage the eye’s optic nerve and result in the vision loss and blindness. It occurs when the normal fluid pressure inside the eyes slowly rises.
Hyperopia/ Farsightedness
Image focused BEHIND retina, cornea too flat or eyes too short. Corrected with plus lenses.
Binocular Indirect Ophthalmoscope/ Indirect Ophthalmoscope
An instrument that is worn on the examiners head and used to view the back of the eye. Used to take stereoscopic views of the fundus.
Intraocular Pressure
Fluid pressure maintained in the eye by the aqueous humor; measured with a tonometer.
IOP
Intraocular Pressure
Keratometer
Instrument used to measure the corneal curvature
Lensometer
Instrument used for determining the power of an eyeglass or contact lens. Measures back vertex power which includes sphere and cylinder power.
Macula
Central portion of the retina surrounding the fovea; responsible for sharp clear central vision. Also for seeing detail.
Macular Degeneration
Disease of the eye, involving loss of structure and function (deterioration) of the macula. Largest cause of irreversible blindness.
Dry and wet types. In dry macular degeneration, the center of the retina deteriorates. With wet macular degeneration, leaky blood vessels grow under the retina.
Monocular
Use of only one eye
Myopia/ Nearsightedness
Image focused IN FRONT of retina, eyes too long. Corrected with minus lenses.
Ocular Adnexa
Part of the external part of the eye examination to rule out any abnormalities or ocular conditions in the adjacent structures of the eye (eyelids, lashes, eyebrows, lacrimal apparatus, tarsal plates, orbit, extraocular muscles and conjunctiva).
Ophthalmoscope
An instrument used in examining the interior of the eye
Palpebral
Conjunctiva that lines the inside of the eyelids
Pantoscopic Angle or Tilt
The angle the frame front makes with the temples when viewed from
the side; lower rims are closer to the face than the upper rims.
PD
Pupillary distance
Perimetry
The study of the visual fields
Peripheral Vision
side vision
Photophobia/ Light Sensitive
Symptom causing pain on viewing a light.
Plus Lenses
A lens that CONVERGES light. Objects viewed through this lens appear larger/ magnified.
Polymethylmethacrylate (PMMA)
Clear plastic material used for rigid contact lenses; first material used after glass. Lacks oxygen permeability.
Presbyopia
Loss of ability to see near due to lens losing ability to accommodate. Usually begins early 40s and requires readers.
Prism
Used to correct patient’s eyes that are not aligned correctly. It is a lens that bends light.
Pseudophakia
Term used for aphakic correction after a lens implant. Ex: IOL following cataract surgery) Replacing crystalline lens with an intraocular lens.
What Is Pupillary Distance?
Distance between the centers of the pupil of each eye.
Radiuscope
An instrument that measures the curvature of a contact lens.
Refraction
Altering of the pathway of light as it passes from one medium to another
Retinoscope
An instrument used to perform refraction. Will indicate refractive error when all motion in every direction is stopped when the light is moved across the pupil.
Retroscopic Angle or Tilt
The angle the frame front makes with the frontal plane of the wearer’s face. When the lower rims are farther from the face than the upper rims
Segment Height (Seg height)
Vertically measured distance from the lowest point on the lens or lens opening to the level of the top of the seg. Height of reading portion of a multi-focal lens (bifocal, trifocal, or progressive segment) as measured from the deepest part of the eyewire to a reference point, such as the lower eyelid (bifocals) or pupil center (progressive addition lenses). This measurement is taken in millimeters.
Slit-Lamp Examination
Examination of the eye performed using a Biomicroscope.
Sphincter
A ring-like band of muscle fibers that constricts a passage or closes a natural orifice
Triage
System for sorting and assigning priorities for medical treatment based on the urgency of symptoms.
Vertex Distance
Distance from the back surface of the lens to the front of the eye (cornea)
What is an Optometrist? (O.D.)
Eye health care professionals state- licensed to diagnose and treat diseases and disorders of the eye and visual system.
What is an Ophthalmologist? (M.D. or D.O.)
Physician doctor of medicine (MD) or doctor of osteopathy (DO) who specializes in the medical and surgical care of the eye, visual system, and in the treatment of eye disease and injury.
Optician
An optician prepares and dispenses eyeglasses, lenses, or related optical devices upon prescription to the intended from a licensed physician or licensed optometrist. Also duplicates, measures, verifies, adapts the fit,
and adjusts eyeglasses to the face. Opticians can grind lenses and shape them to fit an eyeglass frame.
Ophthalmic Medical Personnel (OMPs)
Works with ophthalmologists and their patients. Job duties may include taking patient histories, administering tests and evaluations, taking eye measurements for the purpose of diagnosis, and performing a variety of clinical skills.
Optometric Staff- Paraoptometric
Works under the direct supervision of a licensed doctor of optometry. Job duties may include collecting patient data, administering routine and technical tests of the patient’s visual capabilities, and assisting in office management.
The paraoptometric may assist the optometrist in providing primary patient care examination and treatment services, including, but not limited to, contact lenses, low vision, vision therapy and ophthalmic dispensing, and office management.
What Entity Are Optometrist Licensed By?
The State
Visual Acuity/ Snellen Fraction
Measure of the finest detail the
eye can detect.
Snellen Letters
Letters found on Snellen chart most often used to measure acuity at distance
Snellen Fraction
= Testing distance over the
Distance at which letter is
standardized to be read ( Ex: 20/20)
The numerator (or top number) of the fraction is the testing distance, which is typically 20 feet. The denominator (the bottom number) represents the distance at which that letter is supposed to be read. When you see the Snellen fraction 20/20, for example, it means that the eye reads at 20 feet the letter that is standardized to be read at 20 feet.
Posterior Pole
Refers to the retina between the optic nerve and macular area
Arcades
Normal pattern of retinal blood vessels as they leave the optic nerve head and arch around the macula
Exudates
Protein or fatty fluid that leaks from blood vessels into retinal tissue.
Hard exudates (yellow spots seen in the retina) and soft exudates (pale yellow or white areas with ill-defined edges) Hard is less fluid/more dense. Soft is fluffy looking also called cotton wool spots.
Cotton Wool Spots
Fluffy-looking white deposits (exudates) resembling small tufts of cotton within the retinal nerve fiber layer that represent small patches of retina that have lost their blood supply from vessel obstruction.
Nevus
A mole; small and flat usually pigmented area; benign tumor made of specific cells (called nevus cells) found in skin and eye tissue
Pachymetry
Measures the thickness of the cornea
sphygmomanometer
Measures blood pressure along with stethoscope. Instrument often attached to an inflatable air-bladder cuff and used along with a stethoscope, for measuring blood pressure in an artery.
Refractive Status
Describes how light rays that enter the eye are focused
Non-Compliant Patient
A patient who does not adhere to the prescribed regimen of care and follow-up.
Most common reason patients stop wearing contact lenses.
Alternating Esotropia
The patient fixates with only one eye while the other eye turns in.
What does Visual Field (VF) Testing Determine?
Functional vision (how well you see day to day) also the area of space visible to the eye
Systemic Diseases
Conditions that affect the whole body
Objective Test
Test that DOES NOT require responses from the patient
Subjective Test
Test that DOES require responses from the patient.
Amsler Grid
Simple square containing a grid pattern and a dot in the middle. Can help detect early signs of retinal disease and monitor changes in vision. At home versions should be looked at once a week.
Aberrometry
Non-invasive test that allows studying the optical quality of the visual system. It assesses for vision aberrations (any deviation in normal vision).
An aberration results in light being spread out over some region of space rather than being focused to a point.
Low Vision
Vision loss that cannot be corrected by medical or surgical treatments or conventional eyeglasses or contacts. Can include blind spots, poor night vision and blurry sight.
The most common causes are age-related macular degeneration, glaucoma and diabetes.
What does O.D stand for?
Oculus Dexter (right eye)
What does O.S stand for?
Oculus Sinister ( Left eye)
Monovison
Corrects one eye for distance and other eye for near. Can be used to correct presbyopia.
Aspheric Lens
Provides a wider field of vision.
Spherical Lens
Has same power in all areas of the lens.
What is the amount one prism diopter will bend a ray of light?
1 cm for every 1 meter of distance.
What is the smallest unit of lens measure?
0.25 D (diopters)
Plano
Lens with no power.
What are the five “O” Eye Specalists?
1.) Ophthalmologist
2.) Optometrist
3.) Optician
4.) Ophthalmic Medical Personnel (OMP)
5.) Optometric Staff- Paraoptometric
What Is The Vision Pathway?
1) light rays are refracted (bended) & focused on pupil as they enter through cornea.
Muscles in iris contract / relax controlling amount of light entering pupil
2) lens refracts light more so focused on retina
3) photoreceptors in retina respond to energy from light & generate action
potentials = sent along optic nerve to
brain for processing
Adduction
Turning eye towards nose.
Abduction
Turning eye away from nose.
What is a meridian of the eye?
Considering the center of the pupil as a pole, imaginary lines are drawn around the eyeball that is intersected at the poles at both anterior and posterior positions, which are called the meridians of the eye.
Pinhole Visual Acuity Test
Test is helpful in differentiating whether the sub-normal visual acuity is due to uncorrected refractive errors or eye disease. The pinhole removes scattered light and helps the patient focus more clearly which will allow them to read the Snellen chart more easily.
Photoablation
The procedure using ultraviolet radiation from a laser to remove tissue.
Cycloplegia
A paralysis of the ciliary muscle so accommodation can’t occur.
Ciliary Muscle
Controls the focusing power of the eye by changing the shape of the crystalline lens.
Glaucoma Surgery
Numerous different surgeries that facilitate the escape of excess aqueous humor from the eye to lower the intraocular pressure and a few that lower IOP by decreasing the production of aqueous humor.
