The person may have had mild farsightedness when he or she was young, but because the ciliary muscle had good adjustment ability and the lens had good elasticity when he or she was young, he or she was able to adjust to a low degree. When you are over 40 or 45 years old, the ciliary muscle function of the eye weakens, the elasticity of the lens decreases, and the adjustment function is weakened, so the original prescription becomes apparent and causes blurred vision. Some people wear presbyopic glasses in their 40s, which is related to their own eye development, and like the younger ones, there are now treatments that can be done with excimer laser to solve these problems.