is there any stress in wearing sunglasses? Is sunglasses suitable for everyone?
the summer weather is hot and the sun is aggressive. When you go to the street and travel, you can not only immediately turn into a fashionable “black super” with a pair of sunglasses, but also have a lot of comfortable eyes. However, do you pay attention to wearing sunglasses? Is it suitable for everyone to wear sunglasses?
sunglasses can not be worn if you want to. There are also “contraindications”.
experts say that the enhanced ultraviolet radiation in summer is easy to cause damage to cornea, conjunctiva and crystals. Long term direct exposure to sunlight will also lead to a rapid decline in vision and form myopia, hyperopia, astigmatism or cataract. Therefore, it is very necessary to wear appropriate sunglasses in summer to protect your eyes and avoid prolonged exposure to the sun.
however, there are four types of eye diseases patients can not wear sunglasses at all, namely glaucoma, optic neuritis, color blindness and night blindness.
glaucoma patients:
due to the disorder of aqueous humor circulation and the increase of intraocular pressure, resulting in optic papilla atrophy and visual field defect, resulting in the decline of visual acuity. If you wear sunglasses, it will aggravate the disorder of aqueous circulation in the eye due to reduced light and enlarged pupils, and further increase the already high intraocular pressure, which will not only worsen the condition, increase the patient’s pain, and even cause blindness.
patients with optic neuritis:
wearing sunglasses in patients with this disease will aggravate the conduction disorder of optic nerve, which is unfavorable to rehabilitation.
color blind patients:
panchromatic blind people wear sunglasses. However, because panchromatic blindness is very rare, most of them are partial color blindness, and they only lack the ability to distinguish several colors. If such patients wear sunglasses, it will make color discrimination more difficult.
patients with night blindness:
elderly people with night blindness are not suitable to wear sunglasses because of insufficient vitamin A intake for a long time and the lack of effective supplement of retinol involved in dark visual response in the body. Therefore, the vision of patients will be affected in dim light.
experts specially pointed out that children should not wear sunglasses before the age of 6, because children’s visual function is not yet mature and needs more bright light and clear object image stimulation. Wearing sunglasses for a long time will affect the normal development of vision, and in serious cases, it may lead to amblyopia.
choosing Sunglasses requires professional optometry knowledge
wearing sunglasses improperly will hurt your eyes
at present, citizens choose sunglasses at will and buy them in shopping malls, supermarkets and even roadside stalls. Experts remind that, like wearing close-up glasses, choosing sunglasses also requires professional optometry knowledge, Improper wearing can not block ultraviolet rays, but hurt eyes.
Sunglasses with polarizing function can effectively block more ultraviolet rays. The reflected glare formed by sunlight on sand, water, snow and road often causes eye discomfort and fatigue. The polarization angle and radian of polarized solar lens are designed according to the principle of precision optics to effectively eliminate and filter the scattered light in the beam, so that the light can be put into the visual image of the eye on the light transmission axis on the right track, so as to make the field of vision clear and natural. Like the principle of shutter curtain, the light is adjusted to enter the eye in the same direction to make the scene look soft and not dazzling. But many sunglasses are made of plexiglass or ordinary glass, which has no UV protection function. If you choose this kind of inferior sunglasses, it is easier to damage your eyes, because people’s pupils will expand after wearing sunglasses, and ultraviolet rays are easier to penetrate, which is easier to damage your eyes than when you don’t wear sunglasses.
“can the sunglasses you buy with thousands or even tens of thousands of Yuan prevent ultraviolet rays? It is difficult for glasses stores without professional optometry knowledge to give the correct answer. Therefore, it is best for citizens to go to professional optometry institutions and choose the sunglasses that are most suitable for them under the guidance of professionals.” Experts say.
finally, it is reminded that normal people should pay attention to the following points when wearing sunglasses:
I. the wearing time of
should not be too long to avoid adjusting burden and visual fatigue;
II.
is not recommended to be worn indoors or in places with weak light at night;
III.
wearing sunglasses will reduce vision, contrast sensitivity and three-dimensional space vision. It is necessary to prevent falling and collision.
does the darker the color of the solar lens, the better the UV protection?
many people believe that the color depth of the lens is directly proportional to the UV protection performance, but in fact there is no relationship between the two. Because the color depth of the lens refers to the transmittance of visible light, which can be judged by the naked eye, while the ultraviolet can not be observed by the naked eye. The anti ultraviolet performance of the lens can only be detected by a specific focimeter and spectral analyzer. For example, the transmittance of PC lens coated with antireflection film is as high as 99%, but the anti ultraviolet performance is almost 100%. If the lens cannot prevent ultraviolet rays, the darker the color of the lens, the greater the damage to the eyes. Because wearing dark sunglasses in the sun, the pupil will be dilated due to the reflection of light, and the lens itself cannot prevent the entry of ultraviolet rays. In this way, the ultraviolet rays per unit area are not reduced, but the pupil area receiving light is increased, Therefore, the amount of ultraviolet rays entering the eyes increases, that is to say, wearing dark sunglasses that can not prevent ultraviolet rays is more harmful to the eyes than not wearing sunglasses.