Blind spot is a tiny area at the back of each eye, where the optic nerve passes through the optic disk and out of the eyes. Blood vessels also enter eyes at this place. It lacks photoreceptor cells (rods and cones) in the retina so the light falling at this spot does not form any image. Edme Mariotte observed it for the first time in 1660.
All the vertebrates have a blind spot. Octopus and other cephalopods do not contain a blind spot as 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.
Earlier it was believed that the area where the optic nerve enters should be the most sensitive area but the most sensitive area to light is present laterally to the blind spot. It is known as fovea or fovea centralis. It is a tiny depression present in the yellowish spot called macula lutea. The fovea is the area where the retina is thin and it allows the light to fall directly on the densely packed cones. It is the region of the clearest vision.
So the blind spot is the area where there is no visual perception and the fovea is the region of the greatest resolution.
This was in brief about the blind spot. Test your understanding with MCQs on Structure of Eye, only at BYJU’S.