The Basic Standard For Purchasing Reading Glasses

The correct purchase of reading glasses is very important for people who need to wear reading glasses. Wearing reading glasses, in line with the principle of clear and comfortable, absolutely can not simply consider the price factor, casually buy ready-made glasses on the streets and alleys or even stalls. Because everyone's presbyopia is not the same, the presbyopia of the two eyes may not be the same, there are some people in presbyopia at the same time as far-sightedness, myopia, astigmatism and other vision problems, if wearing inappropriate reading glasses for a long time, not only can not solve the problem, but also cause eye distension, headache and other problems. Therefore, only to the regular optometry shop for optometry, only suitable for their own vision of reading glasses, in order to truly ensure the health of the eyes, it is best to tailor their own reading glasses according to their actual situation.
A good reading glasses is to meet the optical requirements, have a price tag, and wear comfortable. It mainly reflects the following aspects in 2019:
1. The piece type must be relatively wide, due to the collection effect of presbyopia near sight, coupled with reading and writing habits, the monocular axis should be moved downward on the lens when it is far (head-up), and at the same time, it should be moved inward by 2.5mm. When the pupil is generally above and below the midline of the piece, so that the reading glasses have enough field of view, the piece should meet the requirements of the upper and lower height greater than 30mm, not the smaller the better. The narrow slice type within 25mm above and below is generally portable and used for temporary supplementary vision.
2. The front of the glasses should be wide, but the OCD (optical center horizontal distance) should be small. Since the reading glasses users are above middle age, the face shape is full, the horizontal size of the reading glasses is generally 10mm larger than the optical frame, but the near pupil distance is 5mm smaller than the far pupil distance, so the OCD value should generally be 58-61mm for women and 61-64mm for men, and these two requirements should be met at the same time. A larger diameter lens should be used and a larger photocentroid shift should be allowed during production.
3. Reading glasses must be sturdy and durable. Presbyopia glasses are near-use glasses, and the rule of using the eyes of presbyopia is that the reading distance from 40 years old (+1.00D, that is, 100 degrees) needs to be supplemented with +0.50D (that is, 50 degrees) every 5 years. Moreover, the frequency of picking and wearing in the process of use is tens of times that of myopia goggles, so the parts of reading glasses must be strong or high-elastic materials. The anti-corrosion and anti-scratch performance of electroplating must be outstanding, the hardening process of the lens is better, and in general, it is necessary to ensure that the use of no serious deformation, no rust, and no serious friction within 2 years. In fact, in these points, the requirements of a good reading glasses are higher than those of the same grade.