Yes, everyone has a blind spot and it is a small area in the back of the eye where there are no rods or cones to receive light. An object is invisible when its image falls on this spot. In general vision, the brain fills in this blind spot, allowing us to see a total picture.
Light gets into the eye by passing through the pupil. It hits the retina at the back of the eye. The retina is covered with light-sensing proteins. They relay what they sense to the optic nerve which carries the information back into the brain. The problem is, the optic nerve ends in the field of the retina itself. It creates a dark spot.
Most of the time, the other eye will see what’s happening in its partner’s blind, but if the blind spots overlap while looking at a certain object, or if the person is only looking through one eye, the brain just fills in the spot looking at the surrounding picture. Since we have two eyes that can move around, we don’t notice the blind spot often.
Blind spots are a normal aspect of our vision and do not cause any visual problems. A stroke or other brain damage often causes damage to the visual pathway in the brain, and this can cause much larger blind areas in our vision – homonymous hemianopia, quandrantanopia or a scotoma. These can lead to severe impairment of vision and have an impact on everyday living.
Content for this question contributed by Kristie Collins, resident of Taunton, Massachusetts, USA
