Everyone gets presbyopia. Presbyopia is a physiological change that occurs when the lens becomes less elastic with age and the ciliary muscle is no longer tense enough to make changes to the lens. The lens can lose more than 1,000 degrees of adjustability at a rate of 50-100 degrees every five years, resulting in insufficient adjustability when looking close, so everyone will get presbyopia and must wear convex lenses to supplement refractive power. If you are over 40 years old and already have presbyopia, you will have difficulty reading, dizziness and eye swelling, which will affect your life and work. For example, at the age of 40, presbyopia is 100 degrees, and at the age of 50, presbyopia will increase to 200 degrees, regardless of whether or not to wear glasses, and presbyopic glasses also need to be examined. Some elderly people have myopia, farsightedness, astigmatism, etc. If you do not go through the optometry, you can buy a pair of presbyopic glasses to wear, not only can not solve the problem, and sometimes also cause diplopia, eye swelling, vision loss, etc. So when presbyopic glasses, do not delay, with the age of the original with the presbyopic lens degree is not enough, should also be timely replacement. Preventing presbyopia can actually be done by blinking often and turning the eyeballs to exercise the eye muscles, but also by doing more whole body exercises to promote blood circulation throughout the body, which is also good for the eye muscles. In addition, the Chinese herbal medicine such as Chinese wolfberry and cassia seeds in water, also has the effect of nourishing the liver and kidney, clearing the liver and brightening the eyes.