Abstract: A vision testing apparatus and a method for testing vision in terms of contrast sensitivity and spatial frequency response are provided. The apparatus and method utilize a plurality light-polarizing optotypes which are provided on sheets of an oriented polymeric material. The optotypes are presented one at a time to a patient in conjunction with a polarizing filter such that rotation of the filter relative to the optotype will cause the contrast of the optotype to vary from a first condition wherein the pattern of the optotype is indistinguishable from its background to a second condition wherein the optotype is seen at a maximum level of contrast. The patient will indicate the point at which he or she first sees the optotype. The sequential presentation of a series of optotypes having patterns which vary in their spatial frequencies will provide a measure of both contrast sensitivity and spatial frequency response for each patient tested.

Abstract: A visual acuity testing device and method of preparing same are provided, the device being in the form of an optotype as well as a series of optotypes of the same nature, each of which is defined according to a rectangular optotype gridwork including a plurality of rectangular unit areas of contrasting colors or differing contrast properties that are varied in coloration or contrast as desired in order to form a set of optotype characters that exhibit similar peripheral shapes that vary from one another to define readily recognizable optotype characters.

Abstract: A visual acuity testing device and method of preparing same are provided, the device being in the form of an optotype as well as a series of optotypes of the same nature, each of which is defined according to a rectangular optotype gridwork including a plurality of rectangular unit areas of contrasting colors or differing contrast properties that are varied in coloration or contrast as desired in order to form a set of optotype characters that exhibit similar peripheral shapes that vary from one another to define readily recognizable optotype characters.

Abstract: A color-corrected vision testing apparatus and method are provided, such having a blue filtered incandescent illuminating source in a light-occluding housing for high contrast translumination of test patterns also in said housing to obtain improved testing of acuity levels.

Abstract: An improved eye testing apparatus is provided which permits the operator thereof to precisely and clearly designate certain characters of the eye test pattern. The device includes an external stage, a duplicate test pattern on the stage, and a mask having separate designation locations for designating a character of the test pattern at a vision station within the device while simultaneously designating an identical character of the duplicate test pattern.