Also Day Blindness; A condition where it is difficult to see clearly in bright light (e.g. daylight). Hemeralopia is generally viewed as a less severe form of photophobia, but the two are sometimes used synonymously. There are several causes of…

The two alleles an individual has for a certain gene are of different varieties. For genes on the X-chromosome like the L-opsin and M-opsin, males will have only one allele, but females have two. When those alleles are the same,…

The Holmes-Wright Lanterns were a series of Lanterns for color vision testing used by workers - both civilian and military - in the British marine and aviation industries. The Lanterns were created in 1974 to replace the Board of Trade…

Swedish physiologist Alarik Frithiof Holmgren devised this test during his investigations of the Lagerlunda Rail Accident in Sweden in 1875, which at the time was believed to be caused by a colorblind train driver. The test comprises several bunches of…

The two alleles an individual has for a certain gene are identical. For genes on the X-chromosome like the L-opsin and M-opsin, males will have only one allele, but females have two. When those alleles are the same, the female…

A type of neuron located in the retina. It combines information from several Photoreceptors and can be an intermediate step in the Phototransduction Pathway between the Photoreceptors and a Retinal Ganglion Cell. They are very similar to Amacrine Cells. Among…

The HRR Test (Hardy-Rand-Rittler) is a common Pseudoisochromatic Plate test that uses shapes instead of numbers, and is considered to have solved several of the problems indicative of the Ishihara Test (Cole 2006), including: There are plates that test for…

A Color Space for RGB displays containing dimensions for: HueSaturationLightness It is similar to the HSV Color Space, except that the maximum Lightness is always white, whereas the maximum Value of HSV is the nominal color (e.g. Primary red).

Color Space for RGB displays containing dimensions for: HueSaturationValue It is similar to the HSL Color Space, except that the maximum Value of HSV is the nominal color (e.g. Primary red), whereas the maximum Luminance is white.

One dimension of common Color Spaces such as HSV and HSL, generally represented as a number in degrees between 0 and 360, where: 0° = Red30° = Orange60° = Yellow120° = Green180° = Cyan240° = Blue300° = Magenta330° = (Hot)…

A company that uses AI to design Color Correction Lenses. They do not manufacture their own lenses and no major brand has yet licensed their technology. Website

An effect or tool for systematically changing the Hue of a color or image. Using a Hue Shift tool in an image editing software is a quick way to reveal "hidden" information in an image. For example, hue shifting any…

Neurons (namely the Photoreceptors) have a resting potential of about -40 millivolts. This means their inside stands at a slightly lower voltage than their outside when it is not being excited (is exposed to darkness). In order for a photoreceptor…