Abbots Ripton Rail Accident
The Abbots Ripton rail disaster occurred on 21 January 1876 at Abbots Ripton (England), when a passenger train from Edinburgh to London was involved in a collision, during a blizzard, with a coal train. A passenger train travelling in the…
Absorption spectrum
A photoreceptor is defined by which wavelengths of light it absorbs, which is represented by its absorption spectrum. The absorption spectrum is typically simplified into its peak wavelength, i.e. the wavelength of light to which it is most sensitive.
Achromatomaly
https://youtu.be/kYZ00B5O_VQ Achromatomaly is a term that has been posited as a new form of colorblindness or associated with other forms of colorblindness like Incomplete Achromatopsia or Blue Cone Monochromacy. The term was coined by a programmer in 2008 who extrapolated…
Achromatopsia
Achromatopsia is a severe form of colorblindness where subjects experience no or very limited color vision. Causes are diverse, affecting any part of the Phototransduction Pathway from the Photoreceptors to the Visual Cortex. Achromatopsia can be complete, where color vision…
Acquired CVD
Acquired CVD is a type of colorblindness that is not congenital CVD, i.e. it is acquired during an individual's life. There can still be a genetic component to acquired CVD, as some genetic causes of tritanopia are progressive and will…
Adobe RGB
A color space developed by Adobe in 1998. It was designed to encompass most of the colors achievable on CMYK color printers, but by using RGB primary colors on a device such as a computer display. Adobe RGB encompasses roughly…
Adobe Wide Gamut RGB
An RGB color space developed by Adobe, that offers a large gamut by using pure spectral primary colors. It is able to store a wider range of color values than sRGB or Adobe RGB color spaces. As a comparison, the…
Aesthetic
A type of Color Task, where an individual must appreciate or invoke the beauty inherent in a color or arrangement of colors. This often requires building harmonious combinations of colors, such as when picking an outfit. Artistic expression in painting,…
Afterimage
An effect of Photobleaching Photoreceptors. As your retina stares at a color, it will disproportionately Photobleach the Cones that are most sensitive to that color. While the Cones are still Photobleached, exposing them to a white image - which would…
Amacrine Cell
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 Bipolar Cells and a Retinal Ganglion Cell. They are very similar to Horizontal Cells.
Anomaloscope
An anomaloscope is an instrument used to test for CVD and is considered the gold standard to which other tests are compared. The apparatus was invented by the German ophthalmologist and physiologist Willibald A. Nagel (1870–1911) who named it "Anomaloskop"…
Anomalous Trichromacy
Anomalous Trichromacy is the weakest for of CVD. It comes in three flavours: ProtanomalyDeuteranomalyTritanomaly The severity of anomalous trichromacy spans a spectrum from essentially normal color vision to essentially dichromatic color vision.
AO PseudoIsochromatic Plates
A colorblind test published by the American Optical Company starting in 1940. At the outset of WWII, it became difficult for the USA and the allies to procure the two most popular colorblind tests at the time, the Stilling Test…
Arrangement Test
A category of tests for screening or diagnosing CVD where an individual must arrange colored tiles in a gradient. Individuals with CVD will misorder several of the tiles, and the error score correlates to the Severity of their CVD. Common…
Bioptic Driving
A coping method used by Achromats to be able to drive, despite their Day Blindness and not being able to differentiate the color of signal lights. Equipment includes heavily tinted lenses to alleviate Day Blindness, and a small telescopic system…
Bipolar Cell
A type of neuron located in the retina. It transmits visual information from the Photoreceptor (or Horizontal Cell) to the Retinal Ganglion Cell (or Amacrine Cell) and is therefore the second or third cell of the Phototransduction Pathway.
Blue Blind
A misleading name for Tritanopia. The name derives probably from the blue-yellow opponent channel, which is - by definition - skewed permanently to the far yellow side in Tritanopes, typically because they are missing the S-Cones that balance the channel.…
Blue Bottle Butterfly
A genus of butterflies that was found to own at least 15 different classes of Photoreceptors. Previously, no insect was known to have more than 9. They are one of the animal candidates for having the largest color gamut, thereby…
Blue Cone
A misnomer for the S Cone, so called because the cone is more sensitive to blue light than the other photoreceptors.
Blue Cone Monochromacy
A rare form of colorblindness where the individual sees in Monochromacy (grayscale) because only one class of cone is present (S-cone). This disease is an intersection of Protanopia (missing the gene for the L-Opsin) and Deuteranopia (missing the gene for…
Blue Light Blocking
Blue Light Blocking Filters have two general applications: Glasses - Some have suggested that too much exposure to blue light has the potential to damage Photoreceptors, but there is little research to support this. While UV light is known to…
Blue Opsin
A misnomer of the S Opsin.
Blue Weak
A slightly misleading name for Tritanomaly. The name derives probably from the blue-yellow opponent channel, which is - by definition - skewed to the yellow side in Tritans, typically because they are less sensitive to blue light. "Blue weak" infers…
Blue-Yellow
An Opponent Channel as well as a category of CVD where that opponent channel is affected. This includes Tritan defects as well as the hypothetical Tetartan defects. The Blue-Yellow opponent channel is a reformulation of the Tristimulus values (LMS), which…
Blurple
A portmanteau of blue and purple. Individuals with red-green colorblindness have difficulty (or cannot) differentiating between blue and purple, as they are Metamers. Blue and purple are therefore often referred to as a single color called blurple to account for…