Light-sensitive cells in the retina that work best in darkness or dim illuminations.
Glossary of Eye and Vision Terms
Common terms to help you learn more about your eyes and vision
Sclera
The white part of the eye; a tough covering that along with the cornea forms the external protective layer of the eye.
Severe Visual Impairment
Inability to read ordinary newspaper print, even with the aid of glasses, and impairment indicating no useful vision in either eye; includes those who are legally blind.
Total Solar Eclipses
Total solar eclipses occur when the moon completely blocks the sun. The sun’s outer atmosphere (called the solar corona) glows around the moon when it is blocking the sun. Find
Visual Acuity
Measurement of the ability of the eye to perceive the shape of objects in the direct line of vision and to distinguish detail; generally determined by finding the smallest symbol
Visually Impaired
Persons who have some difficulty seeing with one or two eyes even when wearing glasses.
Vitreous Body
Transparent colorless mass of soft, gelatinous material filling the globe of the eye between the lens and the retina.
wet macular degeneration
“Wet” age-related macular degeneration (AMD) generally causes more rapid and more serious vision loss. In this form of the disease, tiny new blood vessels grow under and into the retina.
