Cyanopsia

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Cyanopsia is a medical term for seeing everything tinted with blue. It often occurs for a few days, weeks, or months after removal of a cataract from the eye.

The eye's lens is normally tinted yellow. This reduces the intensity of blue light reaching the retina. When the lens is removed because of cataract, it is usually replaced by a clear intraocular lens allowing more intense blue light than usual to fall on the retina, leading to the phenomenon.

Hayashi and Hayashi (2006) compared visual function in people given yellow-tinted intraocular lenses with that in people given non-tinted intraocular lenses. Those with the yellow-tinted lenses were less likely to report cyanopsia than those with the clear lenses. Hayashi and Hayashi found no differences in visual acuity or in contrast sensitivity between the two groups.They also found that no one reported cyanopsia three months after the cataract operation, suggesting that some form of neural adaptation or colour constancy had taken place.

[edit] Reference

Hayashi, K., & Hayashi, H. (2006). Visual function in patients with yellow tinted intraocular lenses compared with vision in patients with non-tinted intraocular lenses. British Journal of Ophthalmology, 90, 1019-1023.

[edit] See also

• Xanthopsia

[edit] External link

• http://www.psych.ucalgary.ca/pace/va-lab/Brian/acquired.htm for illustrations of various colour deficiencies including cyanopsia.