As of last Wednesday, the 20th of June, it is summer!
During summer, the days are longer and hotter because the sun rises earlier and sets later than it does during the other three seasons. That means we’ll be seeing a lot of the sun for a couple of months!
Did you know that the sun is the Earth’s main source of energy and light? It’s energy and light both come to the Earth as electromagnetic radiation. Electromagnetic radiation (or EMR) has many different forms with which you may be familiar. There are microwaves which are used by the microwave ovens in your kitchens, visible radiation which is the light we can see, and X-rays which hospitals use to see through our bodies.
There’s another type of radiation that the sun sends that is harmful to humans. This type is called ultraviolet radiation (UV radiation). This radiation is very strong and can cause damage to the cells of our bodies. Luckily, the Earth’s atmosphere absorbs the most-damaging of the ultraviolet rays. But the atmosphere can’t absorb all of the UV rays which come to Earth, so we have sunscreen and sunglasses to help protect our skin and eyes from harmful rays.
Sunglasses work by reflecting or filtering the light travelling into our eyes and only allowing visible light (which does not cause harm) to enter our eyes. They use different tints and films on the lenses to filter different types of light. With the various tints, frames, and colors, sunglasses can also be pretty cool-looking!
Sunglasses are a great invention because they keep our eyes safe and healthy when the sun is the brightest. Remember, even when you are wearing sunglasses, it’s not safe to look directly into the sun. So celebrate Sunglasses Day, but also celebrate sunglasses on all of these bright summer days and look great while being safe!