When we cut the distance in half, this doubles what you see. If you can’t see something, then first try to move closer to it. When the object gets nearer the eye, it seems to be larger. This is true for all. When one cannot see what is written in the blackboard, then the first step is to go nearer the blackboard to read what is written in it.
However, sometimes, when you move closer, the eyes do not focus well at that distance. One may be able to see the object better, but not necessarily sharper. If you have a visual impairment, it is important first to accept that they will not be able to see things as sharp as others,but they can learn to use this technique to maximize whatever vision they have left.
So don’t forget to get closer. It’s a simple and easy technique that is sometimes forgotten and neglected!