• 80% of a lifetime sun exposure is obtained before age 18.
• Children from the ages of birth to adolescence are at greatest risk to accrue eye damage from ultraviolet light.
• Immediately after birth, nearly all UV Light is transmitted through the lens to the retina of the infant’s eye because an infant’s lenses have not begun the critical development necessary to block UV Light.
• During childhood, the lens transmittance decreases as the child’s eyes further develop and by the age of 25, the lens absorbs almost all UV Light.
•  UV exposure contributes to the development of many eye disorders such as Photokeratitis, a reversible sunburning of the cornea; Cataracts, a clouding of the eye’s natural lens which reduces vision; and Skin Cancer can develop on the eyelids and surrounding skin.

What is the UV Index?

The UV index is an international standard measurement of how strong the ultraviolet (UV) radiation from the sun is at a particular place on a particular day. It is a scale primarily used in daily forecasts aimed at the general public.

Its purpose is to help people to effectively protect themselves from UV light, of which excessive exposure causes sunburns, eye damage such as cataracts, skin aging, and skin cancer (see the section health effects of ultraviolet light). Public-health organizations recommend that people protect themselves (for example, by applying sunscreen to the skin, wearing uv protective clothing and wearing a hat) when the UV index is 3 or higher. For more information, go to http://www.epa.gov/sunwise/uvindex.html.

UV Index Scale

2 or Less: Low

A UV Index reading of 2 or less means low danger from the sun’s UV rays for the average person:

• Wear sunglasses on bright days. In winter, reflection off snow can nearly double UV strength.
• If you burn easily, cover up and use sunscreen.

Look Out Below

Snow and water can reflect the sun’s rays. Skiers and swimmers should take special care. Wear sunglasses or goggles, and apply sunscreen with an SPF of at least 15. Remember to protect areas that could be exposed to UV rays by the sun’s reflection, including under the chin and nose.

3 – 5: Moderate

A UV Index reading of 3 to 5 means moderate risk of harm from unprotected sun exposure.

• Take precautions, such as covering up, if you will be outside.
• Stay in shade near midday when the sun is strongest.

Me and My Shadow

An easy way to tell how much UV exposure you are getting is to look for your shadow:

• If your shadow is taller than you are (in the early morning and late afternoon), your UV exposure is likely to be low.
• If your shadow is shorter than you are (around midday), you are being exposed to high levels of UV radiation. Seek shade and protect your skin and eyes.

6 – 7: High

A UV Index reading of 6 to 7 means high risk of harm from unprotected sun exposure. Apply a sunscreen with a SPF of at least 15. Wear a wide-brim hat and sunglasses to protect your eyes.

• Protection against sunburn is needed.
• Reduce time in the sun between 10 a.m. and 4 p.m.
• Cover up, wear a hat and sunglasses, and use sunscreen.

Made in the Shades

Wearing sunglasses protects the lids of your eyes as well as the lens.

8 – 10: Very High

A UV Index reading of 8 to 10 means very high risk of harm from unprotected sun exposure. Minimize sun exposure during midday hours, from 10 a.m. to 4 p.m. Protect yourself by liberally applying a sunscreen with an SPF of at least 15. Wear protective clothing and sunglasses to protect the eyes.

• Take extra precautions. Unprotected skin will be damaged and can burn quickly.
• Minimize sun exposure between 10 a.m. and 4 p.m. Otherwise, seek shade, cover up, wear a hat and sunglasses, and use sunscreen.

Stay in the Game

Be careful during routine outdoor activities such as gardening or playing sports. Remember that UV exposure is especially strong if you are working or playing between the peak hours of 10 a.m. and 4 p.m. Don’t forget that spectators, as well as participants, need to wear sunscreen and eye protection to avoid too much sun.

11+: Extreme

A UV Index reading of 11 or higher means extreme risk of harm from unprotected sun exposure. Try to avoid sun exposure during midday hours, from 10 a.m. to 4 p.m. Apply sunscreen with an SPF of at least 15 liberally every 2 hours.

• Take all precautions. Unprotected skin can burn in minutes. Beachgoers should know that white sand and other bright surfaces reflect UV and will increase UV exposure.
• Try to avoid sun exposure between 10 a.m. and 4 p.m.
• Seek shade, cover up, wear a hat and sunglasses, and use sunscreen.

Beat the Heat

It is possible to go outside when the UV Index is 11 or higher. Make sure you always seek shade, wear a hat, cover up, wear 99-100% UV-blocking sunglasses, and use sunscreen. Or you can opt to stay indoors and take the opportunity to relax with a good book rather than risk dangerous levels of sun exposure.

Are the sun’s rays more intense at higher altitudes?

UV radiation increases 4% for every 1000 foot increase in elevation (i.e. UV radiation is 20% more intense at 5000 feet than at sea level)

Can I get sunburned from the sun reflecting on a surface?

UV rays that are reflected can be just as damaging as direct exposure

• Sand/concrete reflects 25% UV radiation
• Snow reflects 85% UV radiation
• Water reflects 100% UV radiation