For the elderly, it may seem difficult to distinguish between presbyopia and cataract, but in fact, there is a big difference between the two. This has little to do with the length of the eye axis, but rather the cloudy lens blocks some of the light from entering. Presbyopia, on the other hand, is a condition in which it is not clear to see near, but clear to see far, and as long as one does not read books and newspapers and do needlework, the impact on life is relatively small. Unlike presbyopia, cataract is a pathological eye disease, while presbyopia is not considered an eye disease but a normal physiological phenomenon. Cataract is an eye disease that can cause serious complications if not treated in time, and in terms of harm, cataract is far more harmful than presbyopia. Cataracts are caused when the lens capsule is damaged due to aging and oxidation, resulting in clouding of the lens, or clouding of the lens due to other reasons such as trauma; presbyopia is caused by the need to change the refractive power through adjustment when the eye looks close, and this adjustment is caused by the gradual hardening of the lens and the decline of the ciliary muscle function. blurred vision. Cataracts not only affect the daily life of patients, but also cause serious eye diseases such as glaucoma, while presbyopia is accompanied by symptoms such as eye swelling and headache, but it is less likely to cause other eye diseases.