Presbyopia, or presbyopia, is a physiological phenomenon, not a pathological condition or a refractive error, but a visual problem that inevitably occurs when people reach middle and old age. It is one of the signs that the body is starting to age, and it will appear that the near vision cannot last. As we age, the lens of the eye gradually hardens and thickens, and the adjustment ability of the eye muscles decreases, leading to a reduction in the ability to zoom. So how can older people detect that they have presbyopia? According to the correspondence table between age and eye presbyopia, most people with good refractive conditions, i.e. no myopia or hyperopia, usually have 100 degrees of eye presbyopia at the age of 45, 200 degrees at the age of 55, and 250 to 300 degrees at the age of 60, after which eye presbyopia generally does not deepen. Presbyopia is not clear to see things near, but a lot clearer to see things far away. If you have cataracts, you will not be able to see far or near clearly, just like your eyes are covered with a veil. If cataracts are not treated in time, they may cause other eye diseases such as glaucoma. Therefore, we remind the elderly that once their vision is blurred, they should go to a regular hospital for a checkup to avoid delaying their condition.