15 Things Your Eyes Are Trying To Tell You About Your Overall Health

10. Mismatched Pupil Sizes

The pupils are the black circles in the middle of the eyeball. They are also usually the same size, normally measuring 2 to 4 millimeters in diameter when a bright light is shone in them, and becoming 4 to 8 mm when in the dark. Pupil dilation is something that cannot be controlled, which means they move involuntarily depending on outside stimuli, growing or getting smaller as a result of how much light they allow in. When someone has unequal pupil sizes, the condition is called anisocoria, which isn’t normally worrisome. But there are times when it could also be a sign of something worse like third nerve palsy, a torn or blocked blood vessel or a brain aneurysm, which can be deadly when left untreated.