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Yes, Your Eyes Can Get Sunburned: The Dangers of Photokeratitis

July 9, 2012 by

Gosh, is it getting hot out there! The temperatures are skyrocketing, the sun is at its brightest, and for many of us, that means spending time in the pool, enjoying the crashing waves of the ocean, relaxing in the sun, or even pursuing some outdoor adventures. We all know how dangerous the sun can be, and we know that sun protection is an absolute must. So we lather on our SPF 50 and go about our day outside. That’s all we really need to do, right?

Your skin isn’t the only part of your body that needs to be shielded from the sun. Your eyes can indeed get sunburned, too. Known as “snow blindness”, “welder’s eye”, or “flash burns”, Photokeratitis is a very real condition that affects your eye’s corneas – in essence, your corneas become “sunburned.” Our team here at Safety Glasses USA has first-hand experienced the damaging effects of photokeratitis, from seeing how the sun can damage the whites of the eyes on a 10 year child to healthy and active thirty-somethings who forget to wear Polarized Sunglasses.

Causes of Photokeratitis

We typically don’t stare directly at the sun (ouch!), so photokeratitis usually occurs when UV rays bounce off a reflective surface and into our eyes. Water, such as the pool or ocean you’re swimming in on a sunny day, unfortunately reflects UV rays exceptionally well, dramatically increasing the risk of your corneas being scorched in the sunlight. Same goes for the bright white of snow, and even sand and concrete! Ever wonder why you’re not supposed to stare directly at a solar eclipse? Photokeratitis is the reason.

Symptoms of Photokeratitis

It’s pretty easy to spot photokeratitis – if your eyes are red or painful, you most likely are experiencing the effects of this condition. Most people experience mild photokeratitis, where your eyes will be red and in light pain for about one to two days. Severe cases include heavy pain in the eyes and lid spasms, and can actually last as long as six days, often requiring the sufferer to wear an eye patch during this time.

Treatment of Photokeratitis

Photokeratitis doesn’t occur immediately – it can be up to six hours after your corneas get “sunburned” until the symptoms really start to set in. Most doctors recommend over the counter pain medications and eye drops to alleviate the pain in your eyes. If you are experiencing severe symptoms, visit your eye doctor immediately, and s/he may subscribe prescription eye ointment and eye patches. Photokeratitis is no miniscule matter – those suffering from a severe case of it are essentially blind while they are recovering from it.

Photokeratitis Prevention

Applying sunscreen to our eyes isn’t exactly a good option, but committing to wearing Polarized Sunglasses that repel harmful UV rays is. Tinted sunglasses aren’t enough – they still allow the pupil to expand and let in UV rays. We suggest keeping a pair of Polarized Sunglasses in your car so that you always have a pair on hand, whether you’re relaxing on a friend’s pool deck or tackling some mountain climbing for the day.

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Shedding Some Light on Night Driving Challenges and Solutions, Part 2

July 3, 2012 by

Shedding Some Light on Night Driving Challenges and SolutionsA great deal of misconceptions exists about night driving, and “night driving eyewear” is actually a highly sought-after product. But there are some significant considerations when searching for them, and there really is no catch-all sort of solution. Before trying night vision eyewear for driving, be sure to employ the tips provided in Shedding Some Light on Night Driving Challenges and Solutions, Part 1 as well as additional tips provided by the AAA Foundation for Traffic Safety.

Lens Color and Night Vision

There are two main reasons people generally look for night driving glasses. First, to enhance contrast and depth perception in dim light. Second, to reduce glare from oncoming headlights. Let’s look at each of these reasons in turn and try to determine if lens color can provide any solutions to nighttime driving vision problems.

Enhancing Contrast and Depth Perception

This goal can only be achieved during the 2+ hour duration before and during dusk or at other times that are dim without being dark. A yellow/amber lens can brighten surroundings using the small amount of light available. But the key is that these lenses require the presence of some light as benefits are lost when darkness fully descends. Once it is fully dark, not much can help improve visibility.

But even with the possibility of a yellow/amber lens improving visibility in some conditions, the use of tint of any sort once dusk hits is controversial. In fact, eye experts at Laramy-K Optical strongly discourage the use of yellow lenses for night driving and even driving at dusk because “ANY tint further reduces the amount of light transmitted to the eye.” They quote Dr. Merrill J. Allen from the Forensic Aspects of Vision and Highway Safety who says that yellow lenses can “actually impair visual performances and retard glare recovery.”

Reducing Glare from Oncoming Headlights

This goal is achieved using almost anything other than clear. However, this need usually applies in the dark when headlights appear even brighter by contrast.  This type of glare is different than that generated by the sun.  Thus, a polarized lens, which is by far the best for reducing sun glare, will not have the same benefit against headlights.  To reduce headlight glare, a dark mirror lens would likely be most effective.  Unfortunately, this type of lens is neither practical nor advisable in the dark. Arguably, the best alternative then is an indoor/outdoor lens that has a light mirror coating over a clear lens. However, even this type of lens only allows 50-60% light transmission, so it will darken not just the view of the lights but your total surroundings as well. Obviously, this presents a danger with the already dark conditions of nighttime.

So what’s the best choice?

Drivers must understand what they are trying to achieve and how important that goal is to them. They must also realize the trade-off for trying to reduce headlight glare. Experts at Safety Glasses USA advise customers to “please choose wisely,” and to cease using any lens if it impairs vision. Customers must realize that there is no perfect or even ideal type of night driving glasses because there are too many variables such as one’s sensitivity to light, one’s natural ability to see in the dark, the varying environmental light conditions and driver objective.

Conclusion

The bottom line remains that having perfect vision for driving at dawn, dusk or nighttime simply isn’t possible. The first approach should be to remove any obstacles to clear vision, such as those suggested in Shedding Some Light on Night Driving Challenges and Solutions, Part 1. Should you choose to experiment with night driving glasses or even with various lens tints, know clearly that eye experts warn against this as a safe option.

Filed Under: Safety News, SGUSA News Tagged With: ,

Shedding Some Light on Night Driving Challenges and Solutions, Part 1

June 20, 2012 by

Dips in the road. Lane demarcations. Headlight glare. Whether or not you wear glasses, driving at night puts a strain on the eyes. In fact, Driving at Night Proves Dangerous for some 32% of drivers who say they struggle seeing at least part of the time at night. This is one reason, states the Federal Highway Administration, that about half of all traffic fatalities occur at night though only about a quarter of total driving takes place then. (Note that drunk driving and drowsy driving contribute largely to these fatalities too.) Unfortunately, there are no clear-cut solutions to the problem many drivers have with seeing while driving at dusk and dawn as well as after dark.Night Driving

While some individuals turn to night driving glasses, which are readily available at retailers, experts express great caution and even warn against doing so. This 2-part series serves to educate the consumer and to somewhat mitigate this controversial topic. In addition, this series will provide additional suggestions for reducing the vision challenges that so many drivers face at night as well as at dawn and dusk.

Sources of Night Vision Problems

Assuring the best night vision possible begins with first making sure the eyes themselves are healthy. This means getting eyes examined regularly and always wearing up-to-date prescriptions. Before deciding to use tinted lenses for nighttime driving, make sure you have taken the following steps to improve your individual driving circumstances.

  1. Clean lenses, windshields and headlights. Make sure all of these surfaces are free of dust and smears. Keeping these surfaces clean goes a long way in reducing eye strain. In fact, with regard specifically to headlights, the AAA Foundation for Traffic Safety says that “even a thin layer of road grime on lenses can block up to 90 percent of light and severely restrict your ability to see at night.” AAA also says that “for maximum glare prevention, keep every surface between your eyes and the road as clear as possible – including both sides of your windshield and your eyeglasses.” Make a habit of cleaning your glasses regularly and clean the windows in your vehicle as well as the headlights at least once a month.
  2. Investigate possible causes of night vision problems. Poor night vision may be a sign of a serious health condition including vitamin deficiencies, cataracts as well as other significant health problems. In fact, the first sign of cataracts is often decreased night vision with blurry vision also being common. Deficiencies in Vitamin A or Zinc can also cause problems with night vision. Sunlight exposure can also cause eyes to struggle seeing at night, which is yet another reason to wear quality sunglasses that protect against the sun’s harmful rays. See your eye doctor when you first experience night vision problems to make sure a treatable health problem isn’t the source.
  3. Use antireflective coating if you already wear prescription eyeglasses. Laramy-K Optical suggests using anti-reflective coating on prescription eyeglasses as the best option for nighttime driving. Doing so can minimize reflections within the glasses themselves, reduce halo problems, and increase the transmittance of light through the lens to the eye. However, and this is significant, if a person does not normally wear prescription eyeglasses, Laramy-K Optical says that an AR coating on any other type of glasses will not be helpful for improving nighttime vision while driving.

The above suggestions provide the best and least controversial routes for improving night vision. Additional solutions such as using tinted lenses or night-vision goggles involve going down a dim road with no clear-cut answers. This topic will be explored in two weeks in Shedding Some Light on Night Driving Challenges and Solutions, Part 2.

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