What Is The Blind Spot In Eye

Edme Mariotte first observed the Blind Spot in 1660. It is a tiny area at the back of each eye, located where the optic nerve passes through the optic disk and out of the eyes and where the blood vessels enter the eyes. The Blind Spot lacks photoreceptor cells (rods and cones) in the retina, so the light falling at this spot does not form any image.

Structure of eye

All vertebrates have a blind spot, except for octopus and other cephalopods. This is because the nerve fibres do not disrupt the retina and pass from behind the retina.

The blind spot of the right and left eye is present at the right and left side of the central vision, respectively. As the visual area of both the eyes overlap, we do not perceive blind spots with both eyes open.

Scotoma is an area of partial alteration or loss of vision within a field of normal vision.

The scotoma in the mammalian eye is an area of partial alteration in the visual field that has degenerated or partially diminished visual acuity. This area is usually surrounded by a field of normal vision and is usually referred to as a “blind spot”.

Humans Have a Blind Spot - The blind spot of humans is located at 12-15° temporally from where the optic nerve leaves and 1.5° below the horizontal meridian. It is approximately 5.5° wide and 7.5° high.

Fovea

Earlier it was believed that the area where the optic nerve enters should be the most sensitive area to light; however, it has since been discovered that the most sensitive area is located laterally to the blind spot. This area is known as the fovea or fovea centralis, and is a tiny depression present in the yellowish spot called macula lutea. The fovea is the area where the retina is thin, allowing the light to fall directly on the densely packed cones, resulting in the region of the clearest vision.

The blind spot is the area where there is no visual perception and the fovea is the region of the greatest visual resolution.

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