Myopia and presbyopia do not cancel each other out. Many people think that myopic people will not get presbyopia when they get older, and that myopia will become smaller and smaller because the two degrees will cancel out, but this is actually not true. Myopia and presbyopia are two different diseases with different causes. Myopia is caused by poor eye habits or congenital genetic factors that increase the refractive power of the eyes, resulting in decreased distance vision, which is blurred when looking at the distance, but normal near vision; while presbyopia is caused by the hardening of the lens due to aging, resulting in a decrease in the regulation of the eyes, so there will be a decrease in near vision, which means that looking at things near It will be blurry. For both conditions, it is recommended to treat them simultaneously, that is, if both myopia and presbyopia exist, two pairs of glasses should be worn, one pair of glasses for near use, that is, presbyopic glasses, and one pair of glasses for far use, that is, myopic glasses.