The shortcoming of the photochromic lenses
In the GFK ( Of the world's top three data consulting group) Data, China's current retail glasses industry scale is about 23. 4 billion yuan, contains a stealth, sunglasses, glasses and other three relevant industries. More than 600 million orthodontic patients, 400 million patients with myopia, 1. 2. 3 billion pairs, after investigation and data collection, we know about China's photochromic lenses market there are 1. 5 million in a year. Around the globe has a population of more than 10 need to wear glasses to correct vision, these are all the photochromic lenses potential, the potential market is very considerable, 2008 time to change color lenses around the global consumption of 5 2 million. Photochromic lenses in development, also need to continue to improve, especially in improving now organic discoloration factor of fatigue resistance and using inorganic color factor two aspects should be enhanced, so the application of photochromic lenses will be more extensive. So what are the disadvantages of photochromic lens? Photochromic lens shortcoming a good photochromic lens can be within the prescribed period of time to achieve the effect of darker becomes shallow, and can effectively intercept the ultraviolet ray, guarantee through visible light enough, however, some inferior photochromic glasses but absorption of visible light, and some even discoloured and inferior products, wearing this lens see objects exceptionally hard, dilated pupils, make the eye muscle and optic nerve in a nervous state, in the long run, this kind of unqualified photochromic glasses can lead to decreased vision instead. In the light BianSeJing films need to guarantee; The same color for each lens, lens in transparent mode, transmission rate is over 80%, in line with the lens national standards, to meet the international standards of various regulations on safe driving, has no effect on drive at night. The following part of the population is not suitable for wearing photochromic glasses. 1. Middle-aged presbyopic patients should not be wearing the photochromic lenses, because if the glazing color lenses to read a book or work in bright light environment, the lens color deepened, will make the light, make the pupil loose big, cause the front Angle of narrow, aqueous humor outflow, can cause glaucoma, etc. Old people wear photochromic glasses carefully, because the elderly eye refractive system, such as the cornea, lens, vitreous body is not so clear and transparent, as young people look at an object need to bright light to see, the color of the photochromic glasses itself will deepen and lead to eye fatigue, affect the eyesight of the eye. Reading glasses just looking at nearby objects, such as reading, reading, writing, do household chores, such as application cases, no strong sunlight indoors, can need not Dai Guang color lenses. 2. Patients with cataracts, glaucoma, wear glazing color lenses can't solve the problem, not only may aggravate, will lead to elevated iop, prompted the onset of glaucoma. 3. Eyes of normal people can wear the photochromic lenses, correcting the vision already so, also solve the problem to avoid glare stimulation. Classified according to the refractive state, but myopia treated respectively as follows: mild myopia, namely the following three baidu myopia, can wear the photochromic lenses, good for the eyes; Moderate myopia, namely to six more than three baidu baidu myopia, can be allowed to wear the photochromic lenses, in the process of wear, want to consider the customer's own adaptation degree; High myopia, the six degrees of myopia, suggest don't wear the photochromic lenses, the edge of the lens is very thick, because of the high myopia turtle even in indoor can't see the sun, the lens will also present a clear color, high myopia patients vision itself is relatively weak, if there is a color in front with a layer of shadow, it will make high myopia patients more difficult, is not good for the eyes, but there are drawbacks. Optical glass lenses, to change color for high refractive power lens will have a negative impact. The thicker the lens, the light transmittance is lower, the thickness of the lens is different, the color of color piece of concentration is different, especially highly negative edge of the lens is center thickness, the density of color edge is also increasing. Color difference will bring Dai Jingzhe vision problems, the color of the high density is very easy to recognize, center color shallow phenomenon, caused by high refractive power and has a very deep surrounding ribbon, for the lens on the contrary, the influence of the middle area very deep color, and the surrounding color shallow, so high myopia wear photochromic lenses when it is important to note that the color difference will make high myopia still exist the glare. 4. For myopic astigmatism and corrected visual acuity less than 1. Patients with 0, unfavorable also wearing the photochromic lenses. In addition, for flat color glasses no must stand on the bridge of the nose, all day under the environment of the ambient light is not very strong, you can remove it. Photochromic glasses while there are many advantages, but when the application must be combined with their own specific circumstances, specific analysis, correctly grasp can play a good role.