Scotopic vision

Scotopic vision is the vision of the eye under low-light conditions. The term comes from Greek skotos, meaning "darkness", and -opia, meaning "a condition of sight". In the human eye, cone cells are nonfunctional in low visible light. Scotopic vision is produced exclusively through rod cells, which are most sensitive to wavelengths of light around 498 nm (green-blue) and are insensitive to wavelengths longer than about 640 nm (red). This condition is called the Purkinje effect.

Physiology

Scotopic vision occurs at luminance levels of 10^−2 to 10^−6 cd/m^2. Other species are not capable of scotopic vision and may have a reduced ability to respond to changes in light levels. Some species, such as dogs and cats, have a much larger number of rod cells than humans and are therefore more adapted to scotopic vision.

Scotopic sensitivity syndrome

Scotopic sensitivity syndrome, also known as Irlen Syndrome, is a condition relating to the interaction of the central nervous system and the eyes at a physiological level with light. The effects of SSS are most noticeable during activities associated with reading, but an individual with the condition may notice the condition's effects in other areas as well.

See also

• Photopic vision
• Mesopic vision
• Adaptation (eye)
• Night vision
• Purkinje effect

References

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  Scotopic vision