Pinhole glasses which are well known as stenopeic glasses are eyeglasses with a series of pinhole-sized perforations filling an opaque sheet of plastic in place of each lens. Because of being combined with certain eye exercises, they could permanently improve eyesight. In other words, pinhole glasses are really useful for nearsighted people and farsighted people. While pinhole glasses are not made of glass at all, but of an opaque substance such as metal or plastic. The user looks through any of the many small holes in the material. Pinholes can bring about clearer vision in all these conditions. Even if pinhole glasses are claimed to be used by people who are both near- and far-sighted, they are not recommended for people with over 6 diopters of myopia.
Yes, it can improve the vision for those with bad eye sight, including the short sighted ones, far sighted eyes and so on. With the scientific design, the pinhole eyeglasses can filter the not normal light and let is light through the holes into the cornea. Then the lens refractive focus will work. The whole process is just like that telescope glasses. However, it is really effective on the improvement of eyes.
As normal glasses, pinhole glasses are made of metal or plastic, but there are many small holes on the lenses. These holes can give you a clearer vision by only let light rays into eyes from the main part of the pupil, which has slightly effective for improving eye vision. It is helpful for reading and doing any work in short distance. And it could help these people who have cataracts to have a better vision because cataracts prevent light to enter the eye. Additionally, it is durable as other glasses but cost effectively. However, it is limited for people who have farsightedness or peripheral vision.