Experts warned us repeatedly that starting directly at the sun without protective eyewear can cause eye damage and result in serious or permanent vision loss.
What happens when you stare at the sun for too long?
When ultraviolet (UV) light from the sun enters the eye, it’s focused through the lens of the eye and onto the retina at the back of the eye. The retina is the light-sensitive tissue lining the inner surface of the eye.
Once absorbed into the retina, the UV rays result in the formation of free radicals. These free radicals start to oxidize the surrounding tissues. They ultimately destroy the rod and cone photoreceptors in the retina. The oxidative damage is referred to as solar or photic retinopathy.
Damage can occur in as little as a few seconds of staring directly at the sun.
Video credit: Science Insider
Why does nothing happen to your peripheral vision?
It should be clear that if you look at the sun directly without protective glasses, your eyes can sustain damage. However, when you don’t look at the sun directly, but look at it from the corner of your eye, how does the aforementioned scenario not still cause any damage to your eye?
Take magnifying glass for example, when you hold the magnifying glass at the wrong angle, nothing happens. This is because the sunlight is not focused into a death ray, and is simply passing through the glass normally without being focused on a single point.
The same thing happens with your vision. When you’re looking directly at the sun, the eye lens focuses the sunlight and the most intense light falls directly on your retina, potentially causing damage. However, when you’re not looking at the sun directly, but rather through your peripheral vision, less light gets into your pupil and subsequently onto your retina. That’s why the sun doesn’t dazzle or cause discomfort when it’s firmly in your peripheral vision.
Simply put, the further a source of light is from the center of your field of vision, the less light gets into your eyes, which lessens your risk of damage.