The reason for loss of vision or specs is dryness in eyes. Initially it may not be bothersome.
Over a long period of time it becomes complicated.
There is very simple exercise.
Make a small point at wall in front of your eyes.
Do not wear specs (glasses). Stand 8-9 inches away from the wall. Stare/ look at the point without blinking for 15 seconds. If you blink close your eyes and restart.
Without blinking move back away from wall about 9 to 12 inches (Now total distance from wall will be 17 to 21 inches). Stare on the point fot 15 to 30 seconds, If you blink do it once more.
You may change the distance according to your number. It should be distance where you can see better without glasses.
Do this once or twice every 2-3 hours.
Within 1 month you will get normal vision.
It may take longer in old cases. But it will sure stop further deterioration of eyes. It will also solve dryness problem of the eye. The comfort level will go up tremendously.