Never make the mistake of using old bottles of eye drops. Drops that have been stored for too long can become infected with germs or moulds as they change chemically. These can be positively dangerous.If your eyesight is weak, you must wear glasses. However, wear your glasses only when you need to. Eye muscles cannot relax as long as you are wearing them.
If you cannot do without glasses, take them off for a few minutes, from time to time, during the day. Take this time off to do some eye relaxing exercises which are given at the beginning of this chapter.
Also people who wear glasses should have their eyes re-tested every two years.