What happens when a patient with an eye disease is seen in the clinic and the ophthalmologist tells the patient that there is no hope for treatment of the eye disease and the patient wants to improve their vision? Please come to the low vision clinic and you may have one last chance to improve your vision and get rehabilitation. The main measure of rehabilitation is currently relying on a variety of visual aids. Optical visual aids are commonly used in clinical practice: they use the magnifying effect of convex lenses or optical systems to make small objects that were not clearly visible to patients with visual disabilities larger. For example, a handheld magnifying glass. With the development of technology, electronic visual aids are gradually used in clinical practice. Electronic visual aids are a kind of electronic graphic magnifying device, which transmits the image to the screen and magnifies the observed items such as the text and pictures read through a camera lens. Electronic visual aids have many advantages over optical visual aids: high magnification, large field of view, normal reading distance and comfortable reading posture, and image inversion change: for example, it can be adjusted to black characters on a white background or white characters on a black background. Contrast and brightness can be adjusted by the visual aids can improve the quality of life of people with low vision, but at the same time, you should know: the visual aids can not replace the function of the normal eye. Wearing a vision aid will not impair the residual vision of a person with low vision.