January 10, 2020
It’s summertime again, and while we’re all excited to spend time outside in the great weather, we all need to be careful of the dangers associated with sun exposure. Most people know to use sunblock, but your eyes are just as vulnerable as your skin, and you need to be careful with them too. If you don’t protect your eyes properly, you can end up with damage that will affect your vision long term.
Luckily, protecting your eyes is pretty easy. All it takes is a little planning and a few things that you can find just about anywhere. So, make sure you follow these three tips to protect your eyes this summer and enjoy great vision for countless summers to come.
Sunlight contains ultraviolet (UV) rays. These aren’t visible, but they can damage your skin and eyes. The three subclasses of UV light interact with your eyes differently. UV-C doesn’t interact at all since it’s filtered out by the atmosphere. UV-B and UV-A reach us, and this is a more significant problem in New Zealand and Australia because we have a thinner ozone layer.
UV-B has a shorter wavelength than UV-A, and they both affect different parts of the eye. UV-B is absorbed by the cornea, the transparent front part of the eye, while UV-A passes through this and is absorbed by the retina. Since sunlight contains both kinds of radiation, too much exposure to it can damage both the retina and the cornea. Front-eye damage can result in problems like keratoconus—the thinning of the cornea—and cataracts, the clouding of the eye’s lens. Even though UV-A is weaker, it can damage the retina over time, leading to macular degeneration. The macula is the central part of the retina and damage to it results in the loss of the middle part of your vision.
So what can you do?
The most obvious way to protect your eyes from the sun is to wear sunglasses. But, it’s important to know that not all sunglasses are created equal. In New Zealand and Australia, sunglasses are graded into categories based on the level of protection they provide from UV radiation. There are five levels, from 0 to 4. Level 0 and 1 glasses offer insufficient protection against the summer sun, and are really just for fashion purposes.
Even with sunnies of a higher rating, some will offer better protection than others. The best are the wraparound kind that block light coming in from the side too. With the flatter kind, you may feel like your eyes are protected while harmful UV rays are still getting into your eyes.
Polarised sunglasses are useful in some situations, too. When light reflects off a surface like water or snow, it reflects horizontally in a single plane, more or less. Polarised sunglasses have a special coating that blocks light angled in this fashion, so if you’re driving or boating, it’s a good idea to get a pair beforehand.
Reducing your overall exposure to sunlight during the day is a very simple way to prevent UV light from damaging your eyes. You’re most exposed out in the open, so finding pockets of shade, particularly during the hottest parts of the day, will significantly reduce your overall exposure.
Of course, it’s no fun sticking to the shade all the time, so wearing a hat is a great way to carry a little bit of shade with you when you’re out in the open. A wide-brimmed hat offers the most significant protection. In fact, research shows that one of these can reduce your eyes’ UV exposure by up to 50%.
Just because you can’t see or feel direct sunlight, it doesn’t mean that UV radiation isn’t there. UV radiation can penetrate cloud cover, even when other components of sunlight are blocked. So, whether it’s bright and sunny, or overcast, be disciplined and protect yourself at all times.
Not every part of the day is equal when it comes to UV exposure. The sun’s position in the sky changes the path that its rays take through the atmosphere on their way to our eyes. The atmosphere partially blocks UV, so sunlight is less dangerous if it travels through the atmosphere for longer.
When the sun is lower in the sky, its rays take an angled path towards us—a longer trip through the atmosphere. As a result, the morning and evening sun is actually less harmful than the midday sun. So, plan your day appropriately. Go outdoors in the morning and evening, and seek shade around midday.
This information is summed up in the UV Index, which will be a part of any reputable weather forecast. A UVI of over 5 represents a high level of danger. If you don’t have access to this information, you can apply a helpful rule of thumb: when your shadow is shorter than your height, the sun is high enough in the sky to be dangerous!
Even for those of us who are the most sunsmart, impaired vision and eye conditions can sometimes be a fact of life. Fortunately, we’re experts in laser and surgical procedures for most major eye-related conditions. With summer coming up, we’re offering interest-free vision correction, too. So what are you waiting for? Book an appointment today!