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

The science and technology of the interactions between sound waves and light waves passing through solid materials, especially as applied to the modulation and deflection of laser beams by ultrasonic waves which are important in laser and holographic technologies: Samuel Waters was intent on perfecting a system of acousto-optics to enable him to expand his holographic business which printed passes for the local bus system.

A measure of the extent to which the index of refraction changes with applied high electric fields; such as, several parts per ten thousand for applied fields of the order of twenty volts per centimeter.

Since the phase shift of a light wave is a function of the index or refraction of the medium in which it is propagating, the change in index can be used to phase modulate the light wave by shifting its phase at a particular point along the guide, by changing the propagation time to the point.

The effect whereby a light beam is deflected by a birefringent prism when its polarization is changed by voltage applied to an electro-optical crystal through which the beam passes.

The deflection of the beam depends on its particular polarization.

The change in the index of refraction of a material when subjected to an electric field.

The effect can be used to modulate a light beam in a material since many properties; such as, light-conducting velocities, reflection, and transmission coefficients at interfaces, acceptance angles, critical angles, and transmission modes, are dependent on the refractive indexes of the media in which the light travels.

1. A material in which the indexes of refraction (a ratio of the speed of light in a vacuum relative to that speed through a given medium) are changed by an applied electric field.
2. A material having refractive indexes which can be altered by an applied electric field.

An instrument that uses an applied electric field to alter the polarization properties of light.

The modulation (variation of amplitude or frequency) of the phase of a light wave; such as, by changing the index of refraction and the velocity of propagation and hence the phase at a point in the medium in which the wave is propagating, in accordance with an applied field serving as the modulating signal.

1. A radar system which collects information by detecting the effects of an electric field on an optical observable fact.
2. A radar system using electrooptic, or electro-optic, techniques and equipment instead of microwave to perform an acquisition and tracking operation.

A device used to control or to block a light beam by means of the Kerr electro-optical effect (a change in rotation of light reflected off a magnetic field).

The inducement of double refraction of light in a transparent substance when a strong electric field is applied in a direction transverse to the beam of light.

In double refraction, the index of refraction (a measure of the amount the ray is bent on entering the material), and hence the wave velocity of light vibrating in the direction of the electric field, is slightly different from the index of refraction of the vibration perpendicular to it.

Optically, the substance behaves like a crystal with its optic axis parallel to the electric field.

This effect was discovered in the latter part of the 19th century by a Scottish physicist, John Kerr.

The same behavior in solids is sometimes called the Pockels effect.

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.

A rare, most commonly benign tumor on the optic nerve or the optic chiasm (the crossing of the two optic nerves).

Optic gliomas cause pressure and destruction of normal optic nerve tissue. They are most common in children and teens.

Optic gliomas are strongly associated with neurofibromatosis.

The second cranial nerve; the sensory nerve that innervates the retina.

Acute impairment of vision in one eye or both eyes, which may be affected simultaneously or successively; and which may recover spontaneously or leave the patient with a scotoma or scotomas; or even blindness.

Scotoma refers to an area of lost, or depressed vision, within the visual field; surrounded by an area of a less depressed, or of normal, vision.

Producing a vision of the mind or soul.

The inability to perform complex or co-ordinated movements: "Visual apraxia takes place when an individual fails to represent spatial relations correctly as when drawing or when involved in some form of construction."