Basic Criteria For Buying Reading Glasses
Buying reading glasses correctly is very important for those who need to wear reading glasses. When you wear reading glasses, you must follow the principle of clarity and comfort. You must not simply consider the price factor and buy ready-made glasses on the streets or alleys. Because the presbyopia degree of each person is different, the presbyopia degree of the two eyes may also be different.Some people also have vision problems such as hyperopia, nearsightedness, and astigmatism while presbyopia. Reading glasses can not only solve the problem, but also cause eye swelling and headache. Therefore, only by going to a regular optical shop for optometry and optics, and only reading glasses that are suitable for your vision, can you really ensure eye health, and it is best to tailor your own reading glasses according to your actual situation.
A good reading glasses meets the optical requirements, has a price tag, and is comfortable to wear. It mainly reflects the following aspects in 2019:
1. The film type must be relatively wide. Due to the collective action of presbyopia in near vision and reading and writing habits, the monocular vision axis should be moved downward when the lens is far-sighted (horizontal) and 2.5 mm inward. The pupils are generally on the middle and bottom of the sheet when looking up. Therefore, to make the reading glasses have enough field of view, the sheet should meet the requirement that the height above and below 30mm. Narrow sheet types within 25mm above and below are generally portable for temporary vision supplementation.
2. The front of the glasses should be wide, but the OCD (horizontal distance of the optical center) should be smaller. Because reading glasses users are all middle-aged and full face, the horizontal size of reading glasses is generally 10mm larger than that of optical frames, but the interpupillary distance is 5mm smaller than the interpupillary distance, so women with OCD values 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 larger diameter lenses and have a larger optical center shift when making films.
3. Reading glasses must be strong and durable. Presbyopic glasses are near-vision glasses. The eye pattern of presbyopia is that the reading distance starts from 40 years old (+ 1.00D, that is, 100 degrees), and you need to add + 0.50D (that is, 50 degrees) every 5 years. In addition, the frequency of taking off and wearing during the use process is dozens of times that of myopia, so the reading glasses must be strong or highly elastic materials. The anti-corrosion and anti-scratch performance of electroplating must be outstanding, and the hardening process of the lens should be good. In general, it should be used within 2 years without serious deformation, rust, or serious distortion. In fact, at these points, the requirements for a good reading glasses are higher than the frames of the same grade.