Hi I’m Craig, and this is Mental Floss on YouTube. Today, I’m going to answer Amar
Jerath’s big question, “Why do you see better when you squint?”
Let’s get started!
In order to answer this question, I’m going to have to talk a little about how the eye
works JUST IN CASE you weren’t paying attention in science class.
So, the whole reason we can see is thanks to our good friend light. While you’re looking
at something, light is entering the pupil. The lens in your eye lives right behind the
pupil and that focuses the light on the retina.
The retina is a layer of tissue containing photosensitive cells, known as rods and cones.
And that’s where the image (of what you see) is created, then that image gets sent
to the optic nerve in the brain. In the retina, there’s something called “fovea,” which
is the part of the eye that makes sharp central vision (a.k.a. detail-oriented vision) possible.
We need that type of vision so we can do stuff like read and drive.
When you look at an object and it appears blurry, that’s usually because of light
too. The lens doesn’t properly focus the light onto the retina. (Unless you have another
eye condition, like cataracts, causing this to happen.)
When you squint, two things change that help you see better: the shape of your eye and
the amount of light entering it. And a third thing, you look like Gilbert Gottfried. If
you know who that is.
First, there’s the shape. When a person squints, the new shape of the eye makes it
so that the light coming into the eye can be focused directly on the fovea. And since
the fovea is the best at getting visual details, that helps us see more clearly.
Second, there’s the amount of light entering the eye. When someone squints, less light
is let into the eye. Blocking out a bunch of unnecessary, excess light makes it easier
for the eye to focus because it’s trying to focus on less all at once.
This can really help when you’re in a bind, but it’s probably worth mentioning that
if you’re frequently squinting in order to see...you might need glasses. Or if you
already have them, you need to stop forgetting to wear them. You go get your glasses. But,
contrary to popular belief, squinting isn't going to damage your vision. It might give
you a headache, but that’s just because of the muscle contraction in your face. It
also might give you these things. What are they called, angel tears? Crow's feet.
Thanks for watching Mental Floss on YouTube, which is made with the help of all these foveas.
If you have a Big Question of your own that you’d like answered, leave it below in comments.
See you next week!