Old-Sightedness ( Presbyopia )

As the normal eye gets to be forty years old, it develops old-sightedness (presbyopia),which makes it diffcult to see reading material, but things at a distance like TV and street signs stay in focus.Old-sightedness should not be confused with farsightedness.
The difference is that as a farsighted eye gets older,everything is out of focus whether it's up close like a book or far away like a street sign.
The only treatment for old-sightedness is to purposely make one eye nearsighted.This is called monovision.