apparent between the ages of 40 and 65. You will then need a pair of glasses to be able to read at a normal distance of approximately 35 centimetres. The power of your reading glasses depends on your remaining [...] ss. What is a vision defect? An eye is described as having a vision defect when it has less than normal vision. The term is very imprecise, as a vision defect can have a wide variety of causes and cha