The Opsin in humans that is excited by the medium Wavelengths in the Visible Range (hence the "M" for medium/middle). The typical form has a Peak Wavelength at 540nm, which is a wavelength that excites green in Color Normals, hence…

A hybrid of the typical M-Opsin and L-Opsin that has a Peak Wavelength between 530nm and 560nm. There is no fundamental difference between M*- or L*-Opsins, and are only called such depending on whether the complementary gene on the same…

A visual representation of Color Contrast Thresholds. The smaller a MacAdam Ellipse, the better an individual's Color Contrast Sensitivity. Every chromaticity within a MacAdam Ellipse should appear identical. A colorblind individual has ellipses that stretch along their Confusion Lines. When…

Also called Age-related Macular Degeneration (AMD); A disease of the retina where vision is lost in the macula, degrading the central vision, but mostly preserving the peripheral vision. There are two types: In dry AMD, cellular debris called drusen accumulates…

Also Fuchsia; A secondary color of the RGB Color Model and primary color of the CMYK Color Model. Magenta is at the center of the Line of Purples. It is therefore a Extra-Spectral Color and a target of the Purple…

A marine invertebrate that at one point was considered to be the animal with the most colorful vision. The mantis shrimp has 12 different photoreceptors. This has since been exceeded by the Blue Bottle Butterfly. While the 12 photoreceptors were…

A type of lantern for testing red-green color vision. It was designed in 1939, but despite being out of production since 1940, it is still used by the Indian military. Since 2013, the military has tried to convert the defunct…

Also Knowledge Argument; A philosophical thought experiment, which describes Mary, a scientist who exists in a black and white world where she has unlimited access to physical descriptions of color, but no actual human perceptual experience of color. The central…

Melanopsin is an Opsin with a Peak Wavelength of 480nm. Unlike Photopsins (Cones) and Rhodopsins (Rods), Melanopsins are not part of any "image-forming" visual system. They are located inside special Retinal Ganglion Cells (nerve cells) in the retina and their…

Mesopic Vision is a fusion of Scotopic Vision and Photopic Vision systems at an intermediate environmental brightness. At these "Twilight" levels, both of these systems are active, since the light is dim enough that the Scotopic Vision is not Photobleached,…

A metallic "color" is one that mimics the reflectivity of a polished metal surface. They cannot be represented as a single color, but are usually represented as a color with specific patterns of Value-variation that give the impression of a…

Colors that appear to be the same to an observer, but have different spectra. For the Colorblind, Colors of Confusion are Metamers (e.g. blue and purple are metamers for red-green colorblind). Even for Color Normals, there are an infinite number…

A type of anomalous trichromacy that combines a red-green defect and blue-yellow defect. A subject with mixed anomalous trichromacy basically independently exhibits tritanomaly and either protanomaly or deuteranomaly simultaneously. Assuming both defects are of similar severity, their vision resembles a…

Light that comprises only a single wavelength of light. This is very rare in nature, where the majority of colors have a broadband Illuminant (e.g. D65 daylight). Some sources of Monochromatic Light includes: Refracted Polychromatic Light, such as a rainbowLasers…

A device that can decompose broadband light into several single-wavelength components. This can be used to measure the spectrum of a light source (wavelength by wavelength), or to isolate a single wavelength from a source to synthesize a monochromatic light…

A Color Correction Lens to be worn over one eye, usually as a contact lens. These lenses consist of a simple red (or Magenta) filter. By itself (if worn on both eyes), a red filter cannot correct CVD, but can…

The Moreland Match is the blue-yellow equivalent of the Rayleigh Match, which detects red-green color vision defects. It is used in blue-yellow Anomaloscopes, such as the Moreland Anomaloscope and was devised in 1979. Typically an observer is shown a circle…

A 3D Color Space, devised in 1905 by Albert Munsell, an American art professor. Similar to HSV/HSL, it specifies colors based on Hue, Chroma, and Value, as seen in the below schematic, and was the first color space to completely…

The protein in dark meat that gives it its deep red color. When the meat reaches a certain temperature, the protein goes through several steps of denaturation and oxidation, whereby it loses its color, and the meat will change color…

A section of a Photoreceptor in the Inner Segment that contains several organelles. Photoreceptor Anatomy