Classic optical reading glasses for men and women
About reading glasses
Good reading glasses meet the optical requirements and are comfortable to wear. Mainly reflected in the following aspects:
1. The lens type must be relatively wide. Due to the collective effect of presbyopia when near vision, plus reading and writing habits, the monocular visual axis on the lens should be moved downwards and 2.5mm inward when it is farther away (horizontal vision) on the lens. When looking up, the pupil is generally above and below the midline of the film, so to make the reading glasses have a sufficient field of view, the film should meet the requirement that the upper and lower heights are greater than 30mm, not the smaller the better. The narrow type within 25mm up and down is generally portable and used for temporary supplementary vision.
2. The front of the glasses should be wider, but the OCD (optical center horizontal distance) should be smaller. Since the users of reading glasses are all middle-aged and above, and their faces are plump, the horizontal size of reading glasses is generally 10mm larger than that of the optical frame, but the near pupil distance is 5mm smaller than the far pupil distance, so the OCD value for women should generally be 58-61mm , Men should be around 61-64mm. To meet these two requirements at the same time, it is necessary to use a larger diameter lens and to have a larger optical center shift during filming.
3. Reading glasses must be durable. Presbyopia glasses are close-up glasses. The eye-use rule for presbyopia is that from the age of 40 (+1.00D, ie 100 degrees) in reading distance, +0.50D (ie 50 degrees) needs to be added every 5 years. Moreover, the frequency of wearing and wearing during use is dozens of times that of myopia glasses, 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, and the hardening process of the lens should be better. In general, it should be ensured that it will not be seriously deformed, rusted, or severely scratched within 2 years. In fact, in these points, the requirements for a good reading glasses are higher than that of glasses frames of the same grade.