![]() Toward the end of his life, Galileo did go blind, but this was more than two decades after his direct solar observations. Later, Galileo's student Benedetto Castelli discovered the projection method for looking at the Sun (using a pinhole camera), which Galileo felt was a far superior method of solar observation. He may even have looked at the Sun through a low power telescope. You've probably been told that it isn't safe to stare at the sun and that watching a solar eclipse without proper eye protection can make you go blind. Galileo found the addition of fog particularly useful, because it allowed Galileo to observe sunspots on the Sun.Īlthough we don't know how often Galileo looked directly at the Sun, we know from his letters that he made several observations. ![]() This not only makes the Sun less intense, it gives the Sun its reddish glow. When the Sun is low in the sky its light must travel through much more atmosphere to reach us. He looked when the Sun was low on the horizon at dawn or sunset, often when somewhat obscured by fogs or clouds. He never looked directly at the Sun when it was high in the sky. This was not one of Galileo's best ideas, but he did try to be careful about it. As part of his work he looked directly at the Sun many times. But Galileo also made naked-eye observations of the heavens. His discovery of the the moons of Jupiter and the phases of Venus changed our understanding of the solar system. According to Dr Karunarathne, sunglasses with a blue and UV filter could do the trick when outdoors, as could avoiding electronic displays at night.Galileo is most famous for his telescopic observations. Blue light is emitted by PC monitors, televisions, your smartphone, and so many other devices, not to mention the freaking sun. It’s easy enough to say, “okay why not just avoid blue light”, but that’s harder to do. Our experiments explain how this happens, and we hope this leads to therapies that slow macular degeneration, such as a new kind of eye drop.” “It’s no secret that blue light harms our vision by damaging the eye’s retina. “We are being exposed to blue light continuously, and the eye’s cornea and lens cannot block or reflect it,” says Dr Ajith Karunarathne, assistant professor at the UT Department of Chemistry and Biochemistry. Can the sun cause temporary blindness Photokeratitis is a painful, temporary eye condition caused by exposure to ultraviolet rays. Because we now understand exactly what the issue is, we can find better ways to combat it. 'What is it Sunshine' out of curiosity but without any hint of worry. ![]() Thankfully, the study has more to contribute than just worries. ![]() All of these cells died when exposed to a combination of retinal cells and blue light, but were fine when only exposed to one of the other. To study the effect, the researchers introduced retinal molecules to other cell types in the human body, including heart cells, neurons, and even cancer cells. And yet, blue light could be causing this in millions of people well before their time. Photoreceptors dying is a well-documented process called macular degeneration, and it’s something most noticed with advanced age. When they’re dead, they’re dead for good.” “Photoreceptor cells do not regenerate in the eye. If you shine blue light on retinal, the retinal kills photoreceptor cells as the signaling molecule on the membrane dissolves,” says Kasun Ratnayake, a PhD student who contributed to the study, in a press release. But without a supply of retinal molecules, they’re useless.Īs it turns out, prolonged exposure to blue light actually causes retinal cells to trigger chemical reactions in the photoreceptors that poison and kill them. The thing is, you’re able to see because of the photoreceptors in your retina. Now, scientists have puzzled out exactly what makes blue light so harmful.Īccording to a new study from the University of Toledo’s optical chemistry research division, blue light is literally poisoning your eyeballs. It’s been known to cause eye fatigue and vision loss, though we’ve never been able to figure out just why that is. Sun exposure may increase the likelihood of developing this condition. Blue light filters are a popular accessory for computers, for good reason. Cataracts Cataracts are a primary cause of blindness worldwide.
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