nictitation.

Excessive winking.

—Layman’s Medical Dictionary, Harry Swartz, M.D., 1963.

night blindness.

Defective night vision. When temporary may be due to a deficiency of vitamin A. When permanent may be due to diseases of the retina. . . .

—Layman’s Medical Dictionary, Harry Swartz, M.D., 1963.

nyctalope.

One who cannot see at night.

—Layman’s Medical Dictionary, Harry Swartz, M.D., 1963.

nyctaphobia.

An unnatural fear of night and darkness.

—Layman’s Medical Dictionary, Harry Swartz, M.D., 1963.

ocular.

1. Relating to the eye. 2. The lens of a microscope or other optical instruments nearest to the eye; an eyepiece.

—Layman’s Medical Dictionary, Harry Swartz, M.D., 1963.

optic.

Relating to the eye.

—Layman’s Medical Dictionary, Harry Swartz, M.D., 1963.

optician.

One who makes lenses or optical instruments. One who sells spectacles.

—Layman’s Medical Dictionary, Harry Swartz, M.D., 1963.

optometrist.

One who measures the seeing ability without the use of eyedrops.

—Layman’s Medical Dictionary, Harry Swartz, M.D., 1963.

ophthalmic.

Relating to the eye.

—Layman’s Medical Dictionary, Harry Swartz, M.D., 1963.

ophthalmologist.

A specialist in the eye and its diseases.

—Layman’s Medical Dictionary, Harry Swartz, M.D., 1963.