First, the abnormally high amount of ultraviolet radiation and just light itself will damage the retinal tissue. However, if you do choose to stare at the sun, with your eye fully open, a few things are expected to happen. The cornea will signal the brain that it is currently burning from too much exposure and to stop looking at the sun. Additionally, the cornea has pain receptors in place to protect other structures and will detect when there is an overwhelming amount of light hitting the eye. Usually, our bodies try to prevent this from happening through a natural defense mechanism: squinting! When we squint to look at the sun for brief moment, this limits the amount of light that enters the eye, therefore preventing any overloading exposure and usually only resulting in a moment of blurry vision.

When you look up at the sun for too long, too much ultraviolet radiation enters the eye, which damages the photoreceptors and proteins in the retina. The sun itself emits ultraviolet radiation, the same type of radiation that gives us sunburns. These signals then travel to the brain via the optic nerve where they are turned right side up and also into images that we see. Then, photons from light are absorbed by photoreceptors in the retina, which turn the energy from the light into electrical signals. In normal cases, when light enters the eye it passes through the cornea, which focuses the light on the retina. Since the cornea is a curved structure, it bends the light so the flipped image is actually projected onto the retina. While this is excellent advice, what actually happens to the eyes when you stare at the sun for too long? The physiology is actually fascinating! Whether it’s from a parent or friend, you’re likely to have heard this tip, especially when younger. We’ve all heard the story: don’t look straight into the sun because it will hurt your eyes.

Staring at the sun damage