Anomaloskooppeja

Anomaloskooppeja are a group of ophthalmic instruments used to assess human color vision by requiring a person to match two fields of light in color and brightness. The most well-known example is the Nagel anomaloscope, a bench instrument that has shaped the standard approach to quantitative color vision testing.

In a typical anomaloscope test, the device presents a fixed reference field and a second field that the subject can alter by adjusting the mixture of two primary colors, commonly red and green, along with control of luminance. The subject repeatedly adjusts the secondary field until it matches the reference field to the observer’s perception. The resulting match point, expressed as a numeric or proportional value, provides a diagnostic fingerprint of the individual’s color perception. This method is particularly effective at distinguishing normal color vision from various forms of color deficiency and can differentiate protanomalies from deuteranomalies, as well as dichromacy.

Anomaloscopes are used in clinical ophthalmology, optometry, and vision research. They support diagnostic workups for color vision deficiencies, guide occupational screening in fields with stringent color discrimination requirements, and contribute to studies of cone photoreceptor function and color processing. The technique has remained influential because it yields quantitative data about chromatic processing and can reveal subtle differences in L- and M-cone sensitivities.

Limitations include the need for patient cooperation and training, sensitivity to lighting and adaptation state, and potential variability due to age or media changes in the eye. Despite these factors, anomaloscopes remain a foundational tool in objective color vision assessment.