I just recently received my first pair of eyeglasses. My eye doctor stated that contrary to popular belief, that wearing the glasses will not weaken my eyes any further. However my sister-in-law went to her eye doctor just last week where her doctor said the exact opposite, that she was wearing her glasses too much, which caused her eyes to weaken. Is this simply a myth? All I can seem to find is personal experiences rather than firm facts.
The Unversity of Illinois Eye & Ear Infirmary - Clinical & Research Facilities website states as a counter to
Myths about Vision and Eyeglasses "Although eyeglasses makes you see better, they cause vision to get worse over time. Eyeglasses will need to be constantly changed with higher powered one."
Of course it is possible that your eye power may also have increased as you age - but this increase would have happened regardless of whether you wore the glasses or not. When children become nearsighted (myopic), usually between the ages of 8 and 12, there is a natural progression in their myopia and a need for a stronger correction over the next few years. These children, as well as nearsighted adults, may believe that glasses have weakened their eyes when their lens prescription needs to be made strong. Glasses, however, do not weaken eyes; they are simply aids to improve vision.
Anecdotally I can add I have been wearing spectacles for short-sightedness since the age of 10, and the power increased every 6 months or so until the age of 16 - after which it has been steady. As per the above article, it would have got that way irrespective of having worn spectacles.
The above link is one side of the story.
On the other hand, William Bates used to advocate not using spectacles,
The usual method to correct faulty vision is by wearing prescribed glasses. But, some people have claimed that this would not improve vision, i.e. not solving the root of the problem.
The first person to publicly spread this message was William Bates of the 1900's. To him, wearing glasses merely makes our faulty vision more persistent. Just as over-strained muscles could improve, our eye can improve with the use of routine eye exercises
With regards to farsightedness, other than this link from an eye care provider - no surprises there - I have come across forums that state "the doctor only asks you to wear them when reading and not always" - Is that what you've been told or heard?
The Readers Digest says
Fact: If you are prescribed glasses for distance or reading, use them. Trying to read without reading glasses will simply strain your eyes and tire them out. Using glasses won’t weaken your vision or lead to eye disease.
This seems generic, but I infer the "glasses for reading" bit covers farsighted users too.