UV and the Effects on the Eye
UV and the Effects on the Eye
UV-C is absorbed by the ozone layer and does not present any threat to our vision. UV-A & UV-B radiation can have long and short-term negative effects on our eyes and vision.
Despite its small size, 2 percent of the whole-body structure, the human eye is the only organ by which visible light enters the body. The sun’s rays are extremely harmful to the eye and a number of mechanisms have developed over human evolution to keep this delicate structure protected.
Natural eye reactions to UV light cause our pupils to constrict, we close our eyelids and squint, minimising the amount of UV that penetrates the eye. The eye is also shielded well by the brow bone; however, these features and reactions can only provide limited protection from extreme UV conditions. Extreme exposure includes reflections from water, snow & sand & the use of sunbeds, welding equipment and lasers. Eye reactions are activated by visible light and not UV radiation, but on cloudy days UV radiation can still be high and cause eye damage. The natural defences of the eye are limited so a good pair of polarised sunglasses are essential for good eye protection.
UV Radiation Checklist
If you answer yes to one or more of these questions, you could be at a higher risk from UV radiation harm to the eyes.
- Do you spend a great deal of time outdoors?
- Do you use sunbeds or a sunlamp?
- Have you had cataract surgery in one or both eyes?
- Are you a welder, work in graphic arts or in the manufacturer of circuit boards?
- Do you take prescribed or over the counter drugs that affects your sensitivity to UV radiation? Check with your doctor some antibiotics, anti-depressants and antihistamines can cause this.
Cataracts are the leading cause of blindness in the world. When we are young the lens in our eyes is crystal clear allowing us to see through them perfectly. As we get older the small transparent disc inside the eye becomes cloudy these patches grow bigger and in turn affect the vision. Cataracts can appear at different ages in individuals, but they appear to be enhanced by UV exposure. Cataracts can usually be successfully removed by surgery with a new lens being implanted to restore vision.
Photokeratitus is a type of snow blindness. This is a very painful eye condition. When your eye is insufficiently protected and then exposed to UV rays or artificial welding flashes. The UV levels can kill the outer surface of the eye leading to blindness. The pain is caused when the dead skin cells shed. Most often the cells regrow quickly & symptoms go usually within 24-48 hours and vision is completely restored.
Pterygium is when the mucous membrane or conjunctiva grows over the white of the eye. These are non-cancerous growths but can permanently disfigure. The exact cause of these growths is not known although over exposure to UV is thought to be an explanation.
Eye cancer is a general term that is used to describe many types of tumors that start in various parts of the eye. Cancer that forms in the eyeball is called intraocular. Melanoma is the most common cancer of the eyeball. Eyelid carcinoma is a variation of skin cancer. Current scientific research suggests that differing forms of eye cancer are associated with long term exposure to the sun and UV. Eye cancer is rare with only around 810 cases diagnosed in the UK every year.
Macular Degeneration is a major cause of vision loss for people over 60. It is caused by cumulative UV damage to the central portion of the retina, the back layer inside they eye that records what we see and sends it to your brain. There are now supplements available that claim to help with this condition. Check with your Optometrist for product details.
It can take many years for Cataracts and Eye Cancers to develop, but each time we expose our eyes to UV light without adequate eye protection we could be adding to the damage and risks associated to these serious diseases. Maui Jim Sunglasses are endorsed by the Skin Cancer Foundation and can be found in our store on Belmont Street
UV - Why we still need it
Some researchers suggest that light- sensitive cells in the eye are important to help regulate our sleep patterns and wake cycles. As people age they tend to survive on less sleep and are prone to insomnia this research in turn becomes more critical.
It is critical that we protect our eyes from UV light and overexposure, but our eyes also need limited exposure t natural light every day to maintain our normal sleep patterns.
Vitamin D is essential for healthy bones and the most natural source of getting your bodies requirement of vitamin D is sun exposure. Experts tell us that 10-30 minutes of midday sunlight, 2 or 3 times a week is enough for healthy levels. Vitamin D cannot be gained through a window or glass door.
Children need more protection from UV than adults. The World Health Organisation suggests that children who spend more time outside are susceptible to retinal damage from UV rays.
Protection from UV rays should begin at a young age as the lens in a child's eye is clearer therefore, UV light can penetrate deeper into the retina and cornea. Getting children to wear eye protection is not always easy, try sunglasses with special bands that fit onto the end tips and wrap around the back of the head to hold them in place.
The importance of outdoor time
It is important that children do spend time outdoors every day. Researchers suggest at least 2 hours 30 minutes on average per day is a healthy amount of time to spend on outdoor activities. Children who spend little or no time outdoors are more susceptible to eye conditions such as *Myopia, short sightedness and astigmatism, therefore, it is very important that children have adequate eye protection when they are outdoors even on cloudy days.
*Give us a call on 01224 643557 to find out more about Myopia Control
How to protect your eyes.
- Never look directly at the sun.
- Wear sunglasses year-round whenever you are out in the sun. Sun damage can occur at any time of the year.
- Choose sunglasses that block 9 to 100 percent of both UV-A & UV-B light. Maui Jim sunglasses carry the Skin Cancer Foundation seal of approval. We carry them in our Belmont Street store.
- Wear a hat with at least a 3inch brim made from tightly woven fabric. Hats can block out as much as half of all the UV rays from your eyes and eyelids.
- Use a broad-spectrum sunscreen. SPF 30 or higher, choose one that is safe for use on your face and around they eye.
- Take extra care around water, snow and sand. the sun’s rays reflect 80 percent more off theses surfaces. The rays then hit your skin and eyes a second time.
- Be aware of clouds, the sun’s rays still pass through the clouds so be aware even on days that are overcast.
- Be altitude aware. UV intensity increase with altitude so be sure to protect your eyes when skiing or climbing.
- Seek shade whenever possible. Especially during time when the sun is most intense between 10am & 4pm.
Protecting your eyes from Short-Wave High Energy visible light
Chronic exposure to short-wave high energy visible light (blue light) may also be harmful to the eyes.. Many digital devices emit shorter wavelength high energy visible blue light.
Blue light is part of the visible light spectrum. The sun emits blue light as do artificial light sources such as LEDS's, computers, Laptops, iPads, smart phones and welding equipment Some types of blue light can be beneficial to regulate our internal biological clocks however, blue light can be harmful to the eyes, especially to the retina. Studies suggest that it is a risk factor for the onset of age-related macular degeneration due to the fact that blue light penetrates all the way back to the retina. Research suggests the amount of time spent in front of digital devices is having a detrimental effects on the eyes due to the close proximity to the eyes that we hold smart phones etc. Blue light from these devices can be especially harmful to children due to their developing eyes.
Tips for protection from Short wave high energy visible light
- Boost your macular pigment. The main blue light absorbing tissue in the eye is the macula pigment. This is the thin layer of yellow tissue that sits over the very centre of the eye called the macula. This pigment consists of three carotenoids: lutein, zoexanthin and meso-zeoxanthin. These carotenoids can be enhanced with supplementation. We have a product instore that can provide such supplementation. Give us a call on 01224 643557 for details.
- Invest in office/computer glasses. Glasses with lenses specifically made for computers have not only your correct optical prescription but correct working distance incorporated to reduce eye strain. These lenses can also be tailored to consider the activities most common during the working day. All our office lenses come with a blue control filter as standard. Give us a call on 01224 643557 and ask for more information regarding our WorkStyle lens.
- Add to your protection level for your normal glasses and add a UV filter. There are also lenses which darken with sunlight and lighten when going indoors. These can also provide good protection from UV light.
- Give your eyes a break. The easiest way to prevent over exposure is by managing the time spent in front of digital devices. use the 20-20-20 rule, every 20 minutes take a break and look at something 20 feet away for 20 seconds.
- Adjust the screen setting on your smart phone. Many of today’s mobile telephones have screen setting which adjust the screen brightness and night time settings. Alternatively apply a self-adhesive screen filter. Research suggests that spending time on digital devices before bed can affect sleep and keep the brain active.
- IOL's - Intraocular lenses are small implanted artificial lenses used in the treatment of cataracts and myopia. The natural lens of the eye offers a certain degree of protection against various light wavelengths like blue light. There has been some industry talk that certain IOL's are capable of filtering out blue light - but the experts are divided. Additional research is needed to determine whether or not there is any merit to the suggestion that IOL's offer blue light protection.