Humphrey Vision Analyser
Analyser, Humphrey Vision
Subjective refractometer utilizing continuously variable-power lenses developed by Alvarez. The image of a target is formed by this variable-power lens and is reflected by a concave mirror situated 3 m away from the patient. The vergence of light entering the eye can be changed by changing the power of the Alvarez lens: spherical, as well as astigmatic, errors of refraction and binocular vision tests can be made. The spherocylinder correction is automatically computed. See Alvarez lens; optometer.