Generally speaking, people tend to associate sun protection with skin instead of eyes. In fact, studies have shown that ultraviolet radiation will lead to keratitis, cataracts, retinal damage and other eye diseases. Thus, delicate eyes need our special care in heat summer days. <br>Don't look directly into the sun. Eyes are more vulnerable. Direct view to sun for a while may lead to temporary giddiness.Long-time direct view will lead to pain, tears, inflammation and blurred vision and so on, thus damage the retina. <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 UV rays with the wavelength of 280nm are most harmful to the cornea, which would result in conjunctivitis. The 290-400nm wavelength UV ray can cause biggest damage to the lens, which is also the reason for cataract. Surveys show that if you bask yourself in the sun for one more hour every day, the rate that you get cataract increase 10%.Well then, I'd like to tell you some preventive measures. <br>If you stay out in the sun, you'd better make use of hat, umbrella and <a href="http://www.bigeyeoptical.com">bifocal glasses</a> to protect your eyes from sunlight. It should be noted that you'd better buy a pair of <a href="http://www.bigeyeoptical.com">bifocal sunglasses</a> of good quality. If your sunglasses are poor in quality, your eyes will suffer instead of benefit. It is necessary for you to have a pair of sunglasses with a special coating that locks UV light in summer.  Medical research shows that it is unnecessary to choose lenses with too dark color. Grey and light grey are more effective in blocking UV rays. If you wear contact lenses, you can choose those with anti-UV function which can block 90% ultraviolet rays.It will be better to wear a pair of <a href="http://www.bigeyeoptical.com">progressive eyeglasses</a>.At noon, the sun is strongest and your skin and eyes are at highest risk. The best way to protect you is to keep indoors.