Glasses are not only a tool for correcting vision, but also a fashion accessory. Nowadays, large frame glasses such as retro mirrors and polygonal metal mirrors are favored by consumers. Eye experts remind that the blind pursuit of large discount prescription glasses, the optical center distance of the lens once greater than the pupil distance, easy to cause visual fatigue of the wearer, affect vision correction, and even cause damage to the eyes.
Wang Yang, optometrist in charge of the ophthalmology department of the Second Hospital of Lanzhou University, said that the choice of the frame is very important, and the size of the frame will affect the optical center distance of the lens. If the optical center distance of the lens does not match the pupil distance of the wearer, it will affect vision correction. At present, the popular retro mirror and polygon metal mirror frame are too large, and the optical center distance of the lens is greater than the pupil distance, which is easy to cause the wearer vertigo and eye pain, resulting in visual fatigue, and long-term wear will damage the eyes.
"Especially for teenagers, the pupil distance is small, and it is not recommended for teenagers to wear glasses with large frames." 'he said.
Some consumers often choose online opticians. Wang Yang believes that although online matching glasses is convenient, it lacks the important step of correcting and adjusting the frame according to the face shape, and the correction effect may be affected.
Unqualified dispersion coefficient misleads consumers
Similar to the "false label" of the refractive index item of the resin lens, there is also a "false label" phenomenon of the dispersion coefficient. Dispersion coefficient is an important parameter that reflects the imaging performance of resin lenses and directly determines the clarity of lenses. In general, the higher the dispersion coefficient, the better the clarity of the lens image. However, the test found that 4 batches of the dispersion coefficient of the resin lens were unqualified, and the marked dispersion coefficient had a large gap with the actual value.
Among them, the dispersion coefficient marked by a sample lens is 38.5, but in fact, it is only 34.6 after detection, and the deviation reaches 10%, far exceeding the requirements of the standard of plus or minus 4% tolerance. Inspectors said that this will seriously mislead consumers about the clarity of the lens understanding and choice.
15 batches of products from 15 companies were unqualified
It is understood that the resin lens must be marked on the outer packaging of the top focus, diameter, refractive index, dispersion coefficient, light transmission and other performance items and parameters, in order to facilitate consumers to understand the quality status. However, it was found that the top focal power, refractive index, dispersion coefficient and other items have a common "false label" problem, and the actual performance of the sample is seriously inconsistent with the label. And the phenomenon of virtual labeling exists at the same time, is part of the project "non-standard" phenomenon, individual sample lenses even the factory address and production license number are not marked, according to the relevant standards, but also judged as unqualified products.
In the end, the State Administration of Quality Supervision, Inspection and inspection of 80 batches of products from 80 enterprises across the country found that 15 batches of resin lenses from 15 enterprises named Zhenjiang Aoshen Optical Co., LTD., Jiangsu Aodi Optical Glasses Co., LTD., Zhejiang Oriental Optical Technology Co., Ltd. were detected as unqualified refractive index, dispersion coefficient, light transmission ratio, marking and other items. Among them, a resin lens top focal deviation of Danyang Benz Eyewear Factory even exceeds 8 times the national standard, which is a seriously unqualified product.
