Glossary

AMD - Advanced Macular Degeneration
The destruction and loss of photoreceptors in the macular region of the retina resulting in decreased or loss of central vision.

Amsler Grid
A hand-held chart featuring horizontal and vertical lines either black on white, or white on black, used to test for central vision defects.

Antioxidants
Micronutrients that destroy or neutralize free radicals, those molecules which have been identified to cause the stimulation of abnormal cellular reproduction (cancer) and cellular destruction (aging).

Beta-carotene
A member of the carotenoid family of vitamins found in vegetables, especially carrots.

Carotenoid
A nutrient group important to our eyes, usually found in fruits and vegetables.

Central Vision
The area of your vision which shows you what is directly in front of you.

Color vision
The ability to distinguish between color, including hue, saturation and brightness.

Cones
Light-sensitive retinal cells that permit sharp vision in bright light and allow for color discrimination. These cells are shaped like cones.

Cornea
The clear outer portion of the eye that covers the iris and allows light through the pupil.

Drusen
Fatty, yellow deposits or spots that build up under the retina.

Eccentric Viewing
Viewing objects using your peripheral vision.

Fovea
The functional center of the macula which contains the highest density of cones (color sensors).

Functional Vision
The ability to use peripheral vision to get around. People with AMD, and no other condition, will maintain functional vision.

Legal Blindness
20/200 vision in your best eye. In other words, while wearing glasses or contacts you see objects clearly at 20 feet what a normal eye sees clearly at 200 feet.

Lens
A clear structure behind the pupil which helps to focus light onto the retina.

Low Vision
Visual impairment that cannot be corrected by standard eyeglasses, contacts, medication or surgery and that interferes with the ability to perform everyday activities.

Low Vision Specialist
A doctor which specializes in the evaluation of low vision. This person can prescribe visual devices and teach people how to use them.

Lutein
A carotenoid, similar to beta-carotene. Lutein is found in the lens and retina, primarily in the macula. This important nutrient acts as a blue-light filter.

Macula
The retinal region responsible for fine visual details.

Neovascularization
The formation of new blood vessels often fragile and inappropriate for the location.

Ocular
Pertaining to the eye.

Optic Nerve
The nerve that sends vision messages between the brain and the eye.

Optician
A trained professional, who grinds, fits and dispenses prescription glasses.

Ophthalmologist
A medical doctor who specializes in eye and vision care. Can prescribe medication and is trained to provide the full spectrum of eye care from prescribing glasses or contacts, to complex eye surgeries.

Ophthalmoscopy
Examination of the internal structures of the eye using illumination and a magnification system.

Optometrist
A doctor who examines, diagnoses, treats and manages eye diseases and disorders. These doctors also prescribe eyeglasses, contact lenses and medicines to treat eye conditions.

Peripheral Vision
Provides general awareness of objects on either side of the central focus of vision. Also referred to as side vision.

Photoreceptors
The rod and cone cells of the retina that absorb light and allow images to come through to the retina and more specifically to the macula.

Pupil
The round black opening in the iris that allows light into the eye and onto the retina.

RPE (Retinal Pigment Epithelium)
A layer of cells crucial to the light-gathering rods and cones. One of the first layers to experience damage in AMD.

Retina
The back surface inside the eyeball, opposite the lens. An image projected by the lens onto the retina is sensed by the rods and cones as different intensities of light and different colors.

Retinal Specialist
An ophthalmologist who specializes in diseases of the retina.

Rods
Light-sensitive retinal cells that make it possible to see in dim light. These cells are shaped like rods.

Scotoma
The spot where damage to central vision has been great enough to cause loss of normal vision.

Visual Acuity
The ability of the eye to identify details; it is this vision that AMD erodes.

Zeaxanthin
A carotenoid derived from fruits and vegetables. Zeaxanthin, like lutein, is uniquely concentrated in the macula where it protects against blue light and oxidative damage.