Presbyopia, or presbyopia, is a normal physiological phenomenon. It is neither a pathological state nor a refractive error. It is a visual problem that must occur after people enter middle-aged and old age, and it is one of the signs that the body is beginning to age.

Its cause is: as the age grows, the eye lens gradually hardens and thickens, and the adjustment ability of the eye muscles also decreases. Presbyopia will gradually produce close reading or work difficulties, and a series of visual fatigue symptoms such as eyestrain, eye swelling and pain, eyelid twitching, dry eyes, photophobia and tearing, headache, dizziness, nausea, irritability and so on during close reading.

Many people around me have presbyopia, and when they see things blurry, they usually buy a pair of reading glasses that can "see clearly" in an optical shop or on the street. They feel that presbyopia does not require optometry. Sunglasses are cheap. In addition, it is also common for couples to share a pair of reading glasses and not change them all the year round. In fact, there are many specialties in wearing reading glasses. Incorrect wearing methods will not only not work, but will also cause damage to the eyes.