op-, opt-, optico-, opsi-, opso-, -opia, -ops, -opsia, -opsis, -opsy, -optic, -opic, -opy +

1. Characterized by a visual defect in which distant objects appear blurred because their images are focused in front of the retina rather than on it; nearsightedness.
2. Relating to the lack of discernment or long-range perspective when thinking or making plans.

A visual examination, and dissection of a dead body, to determine the cause of death or any changes that were produced by disease.

Dim or cloudy vision from lessened transparency of the ocular media.

1. Night blindness; failure or imperfection of vision at night or in a dim light.

Smoking tobacco may impair the ability to see at night. Hypoxia associated with being above sea level in an aircraft will also decrease night vision.

2. The inability to see well under scotopic (dark) conditions, due to faulty rod function.

The “rod” used here refers to any of the photoreceptor cells of the retina serving scotopic vision. “Scotopic vision” designates the dark-adapted state of vision, in which color perception is replaced by shades of black and white. It is served by the rod photorecptors.
3. A condition of the eyes in which the person can see well during the day, in a strong light, or on bright days, but see poorly at night, in a faint light, or on dull or dark days; night blindness; day sight.
4. The opposite of nyctalopia is hermeralopia, or day blindness.

Reduction, or dimness, of vision at night without visible eye changes.

Night blindness; failure or imperfection of vision at night or in a dim light, with good vision only on bright days.

An eyelash, or eyelashes.

Characterized by a visual sensibility to light stimuli.

Concerned with, or descriptive of, the eye or vision.

1. Belonging to, or relating to, the sense of sight.
2. Relating to, or producing, light that can be seen.
3. A description of an instrument or device that is sensitive to light.
4. Describing a lens that is designed to correct, or to enhance, faulty vision.MBR< 5. Belonging, or relating to, the science of optics.

A lens, or mirror system, that concentrates radiant solar energy in a concentrating photovoltaic system (devices that absorb solar energy turned into electricity) in order to increase electrical output.

The visual angle formed by the optical axes of the two eyes when directed to the same point.

Loss of the ability to name an object clearly seen until it has been perceived through some other sense; such as hearing, touching, smelling, or tasting.

A deterioration in the fibers of the optic nerve resulting in partial or a complete loss of vision.

It may be caused by damage to the nerve from inflammation or injury, or the atrophy may be a result of a disease in the eye.

1. The circular area in the retina that is the site of the convergence of fibers from the ganglion cells of the retina to form the optic nerve.
2. Otherwise known as the "blind spot" of the eye, the disc is the beginning of the optic nerve; the point where nerve fibers from the retina's rods and cones (the light-sensitive and color-sensitive cells) leave the eyeball.