glossary

In biology, photophobia (adjective: photophobic) refers to negative response to light. Also called “light sensitivity” this is an excessive sensitivity to light and the aversion to sunlight or well-lit places. In ordinary medical terms photophobia is not a morbid fear, but an experience of discomfort or pain to the eyes due to light exposure. May be associated with excessive tearing. There can be many causes including inflammation of the iris or cornea. Extreme sensitivity to, and discomfort from, light. May be associated with excessive tearing.

A condition of “light adaptation” that is used in retinal testing such as the electroretinogram. Light adaptation is accomplished by exposing a patients eyes to diffuse light of moderate intensity several minutes. This can be useful for determining the health of “cones,” the fine detail and color perceiving cells in the retina.

Lens material characterized by lightness, impact resistance, high refractive index, UV absorption.