What is a blind spot?
Q: What is a blind spot?
A: A blind spot is a part of the visual field where the optic nerve passes through the optic disc of the retina causing a lack of light-detecting photoreceptor cells, resulting in the brain receiving no information from that area.
Q: Why is a part of the visual field not perceived in a blind spot?
A: No cells are available to detect light on the optic disc, resulting in a part of the field of vision not being perceived.
Q: How does the brain overcome the blind spot?
A: The brain fills in the blind spot with surrounding detail with information from the other eye, so it is not normally perceived.
Q: Which animals do not have a blind spot?
A: Cephalopod eyes do not have a blind spot because the optic nerve approaches the receptors from behind, thereby not creating a break in the retina.
Q: When was the first documented observation of the blind spot made?
A: The first documented observation of the blind spot was in the 1660s by Edme Mariotte in France.
Q: What was the prevailing theory before Mariotte's discovery about the optic nerve entering the eye?
A: Before Mariotte's discovery, it was generally thought that the point at which the optic nerve entered the eye should be the most sensitive portion of the retina.
Q: What did Mariotte's discovery disprove?
A: Mariotte's discovery disproved the theory that the point at which the optic nerve entered the eye should actually be the most sensitive portion of the retina.
