The pinholes on this kind of glasses can filter out abnormal light, and the central part of a beam of light will enter into eyes and focus on the retina, then image become clearer. Wear this kind of glasses can correct ametropia and all sorts of poor vision, such as photophobia, myopia, astigmatism, presbyopia, etc. In particular, it could prevent myopic degree from deeper and correct pseudo myopia, reduce the radiation from TV or computer, What is more, it could reduce eye fatigue and tension. But there are some tips you must remember: first, you do not need to wear it if you have a normal vision, because it may interfere with your vision. Second, do not do dynamic activities such as drive car, ride bike when you are wearing pinhole glasses. Third, do not look into the sun and it is unnecessary to wear if you want to see something nearly (under 30 centimeters). Forth, use 3 to 5 times a day, each time 15 minutes, you can extend time if you intend to watch TV or use computer and it will protect your vision effectively.