Generally speaking, people tend to associate sun protection with skin instead of eyes. Actually, some studies suggest that UV rays are really harmful to eyes and may cause keratitis, cataracts, retinal damage and so on. Therefore, we should pay attention to eye protection from sunshine. <br>Don't look directly to the sunlight in the hot sunny days.The eye is a delicate tissue. One may feel dizzy after looking up to sun for a short while. Direct view to sun for a long time may bring about damage to eye and retina, accompanied with pain, tears, inflammation and blurred vision.<br>It is believed eyes are the most sensitive part to the UV rays; they can absorb a broad range of wavelengths of ultraviolet rays.The 280-nm wavelength UV ray does the greatest injury to the cornea. It is likely to cause conjunctivitis.The 290-400nm wavelength UV ray can cause biggest damage to the lens, which is also the reason for cataract. Research indicates the risk to suffer from cataract rises by 10% if one more hour every day people expose to the sun. And now we should talk about some precautions. <br>When you are outgoing in summer, remember to wear broad-brimmed hat or use umbrella, a pair <a href="http://www.bigeyeoptical.com">bifocal eyeglasses</a> is most effective in protecting your eyes. It should be noted that you'd better buy a pair of <a href="http://www.bigeyeoptical.com">bifocal sunglasses</a> of good quality. Inferior sunglasses will hurt your eyes rather than protecting eyes. They may cause mydriasis. Prepare a pair of UV-cut sunglasses for summer use, and you will benefit a lot.  Medical search results have proved that grey lenses are the best choice; lenses of too dark color may pass more UV rays to eyes. It is better for contact lens wearers to buy anti-ultraviolet ones which cut 90% ultraviolet rays. It would be safer to add a pair of <a href="http://www.bigeyeoptical.com">progressive eyeglasses</a>. Don't work or do activities outside at noon because the sum at that time is strongest and prone to hurt skin as well as eyes.