A blind spot , scotoma , is a vagueness of the visual field. A particular blind spot known as where the physiological blindness , "blind spot", or punctum caecum in the medical literature, is a place in the visual field associated with the lack of photoreceptor cells that detect light on the optical disc of the retina where the optic nerve passes through the optical disk. Since there is no cell to detect light on an optical disc, the corresponding portion of the visual field is not visible. Some processes in our brain insert a blind spot based on the details and information around it from other eyes, so we usually do not see blind spots.
Although all vertebrates have this blind spot, cephalopoda eyes, which are just superficial, do not. In it, the optic nerve approaches the receptor from behind, so it does not make a break in the retina.
The first observation of the phenomenon was in the 1660s by Edme Mariotte in France. At the time it was generally thought that the point at which the optic nerve enters the eye should be the most sensitive part of the retina; However, Mariotte's discovery denied this theory.
Blind points are located around 12-15 Â ° temporarily and 1.5 ° below horizontal and approximately 7.5 ° high and 5.5 ° wide.
Video Blind spot (vision)
Blind point test
Maps Blind spot (vision)
See also
- Filling-in
- Horizontal eccentricity
References
External links
- "Amsler Grid" Test from Ossibus Software
- Blind spots
- Blind point test The blind spot map tool
Source of the article : Wikipedia
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