What Is the Eye’s Blind Spot?
The blind spot is a small area of each eye’s retina where the optic nerve exits. It has no light-sensing cells, so anything whose image lands there simply isn’t seen. Everyone has one in each eye, sitting about 12 to 15 degrees toward the temple from where you’re looking. You never notice it in daily life because your brain fills the gap from the surrounding scene and your other eye.
Find your blind spot →Where it comes from
Your retina is lined with photoreceptors — except at one spot, the optic disc, where roughly a million nerve fibers gather and leave the eye as the optic nerve, and blood vessels enter. There’s no room for receptors there, so that patch is genuinely blind. It sits on the nasal side of each retina, which is why the blind spot appears in your vision toward the temple side, a little below eye level.
Why you never notice it
Two reasons. First, your two eyes overlap: what one eye misses, the other sees, so with both eyes open there’s no gap. Second, even with one eye closed, your brain fills in the missing patch using the surrounding pattern — a process you can catch in the act with a blind spot test, where a dot vanishes and reappears as it crosses the spot.
The physiological blind spot is completely normal anatomy in every healthy eye. A different thing — a new blank or missing area in your central vision that doesn’t fill in — is not normal and is worth an eye exam.