Photonics Dictionary: V

A spectrograph that functions in a vacuum and therefore eliminates any air-absorption of the emission being surveyed.

The angular relation between two light rays that originated at the same object point. Sometimes used to indicate the angle between the visual axes of the eyes.

Virtual reality (VR) is a computer-generated simulation of a three-dimensional environment or experience that can be interacted with and explored by an individual using electronic devices, such as a...

The maximum distance at which the eye can perceive and evaluate objects.

That region of the electromagnetic spectrum to which the retina is sensitive and by which the eye sees. It extends from about 400 to 750 nm in wavelength.

That term pertaining to the spectral region that can be perceived by the eye.

The processes in which luminous energy incident on the eye is perceived and evaluated.

An imaginary line between the object, through the nodal point of the eye, and the fovea, or point of finest retinal acuity.

The angular field of view that is seen by the eyes when fixed on a point straight ahead. The normal binocular visual field is approximately 130° in diameter.

A series of high contrast block letters or similar objects arranged to permit the evaluation of eyesight in humans.

The transparent fluid that fills the portion of the eye between the eye lens and the retina (the posterior chamber).