With the advent of summer the sun’s power is more and more fierce, shining people’s eyes can not open. When the sun is projected on the road or water, those reflected back to the light will directly stimulate the eyes, so that people feel dazzled, fatigue, can not be sustained vision, will lead to a rapid decline in vision, the formation of myopia, hyperopia, astigmatism, or cataracts. In addition to umbrellas and hats to shield the sun, sunglasses are the best weapon against ultraviolet rays. However, wearing poor quality or inappropriate sunglasses can cause headaches, eye pain, fatigue and other discomforts, and in serious cases, even vision loss or aggravation of their own diseases. Have you chosen the right sunglasses for the hot summer? Wearing sunglasses is to prevent ultraviolet rays from entering the eyes, and the ability to prevent ultraviolet rays is not dependent on the color concentration of the lenses, but is determined by the ultraviolet absorber in the sunglasses material. If you wear a poor quality tinted glasses without UV protection, more dangerous than not wearing sunglasses, because the human body has an instinctive reaction of self-protection, the eyes encountered bright light, the pupil will naturally become smaller, so that the UV energy into the eyes is reduced, once wearing glasses without UV protection, will make the pupil dilated, coupled with the role of this kind of glasses do not have isolation of UV rays, the eyes are equal to the gateway to open up, allowing UV invasion, and the energy of UV. Allow ultraviolet invasion, and the energy greatly increased, the damage to the eyes can be imagined. In addition, unqualified sunglasses may come with a refractive index that should not be there, people with normal vision wear these sunglasses, equivalent to wearing a pair of myopic or hyperopic lenses, the eyes will be greatly affected. In summer, many young parents for their children with a pair of small sunglasses, walking on the road is very cute. 6 years old children’s eyes in the process of development of the retina needs enough clear light stimulation, if wearing time is too long, the fundus macular area relative to the lack of effective stimulation may affect the further development of vision, resulting in poor sensitivity to vision, and severe visual deprivation can also cause amblyopia. Therefore, in addition to the need to wear sunglasses when the sun is strong, generally try not to give children sunglasses for decoration. And wearing sunglasses should not be too long, in the indoor should take off the sunglasses. For people with eye diseases, wearing the right sunglasses is even more important. In addition to effectively eliminating and filtering out scattered light in the beam, ultraviolet rays, but also to block harmful blue light. Short-wave blue light is extremely harmful to human eyes, it can penetrate our lens and vitreous body, directly to the most important macular region of the retina, stimulate the retinal pigment epithelium atrophy, cause the death of light-sensitive cells, which leads to vision loss or even completely disappear. For patients with retinal diseases such as retinal macular degeneration, harmful blue light will further accelerate the deterioration of the condition. The normal crystalline lens of a healthy eye is often effective in filtering out this harmful light, but for patients who have undergone IOL implantation, the filtering of harmful light is greatly diminished. Medical references for different lenses: Early cataract stage Amber, yellow, red Congenital iris loss, keratoconus Gray, blue, silver Age-related macular degeneration Amber, yellow, red Retinitis pigmentosa Amber, yellow, red Post cataract/excimer surgery Amber, gray