Eyeglasses Used for Magnification

Adapting to low vision should start with a comprehensive eye examination to optimize your vision with the best eyeglass prescription. This prescription is for distance and near viewing. What defines those with low vision is that even with the best prescription, they are unable to get perfect vision.  More is needed.

Distance glasses cannot be made stronger to improve far away vision.  The next blog will address telescopes and binoculars, which are used to magnify the distance.

Near vision can be improved by strengthening the eyeglass prescription to magnify.  Here is your physics lesson for the day:

the greater the dioptric power (D), the shorter the focal length.

Translated that means:

The stronger the lens magnifying power, the closer objects need to be held to the lens in order to be seen clearly.

Magnifying eyeglasses
Magnifying eyeglasses

Most people will accept a closer working distance.  There may be a point when the lenses are made stronger, where it feels too close.  This is when other magnifying devices are implemented. Things like hand and stand magnifiers, and video magnifiers.

The advantages of high powered reading glasses are that they can have a larger field of view and are hands-free, which means that those with hand tremors will fare better with magnifying eyeglasses.  The disadvantage is that the stronger the lens power, the thicker and heavier the lens becomes, which can result in a heavy pair of eyeglasses.

How to find the focal length of the magnifying glasses:

 We learned in the discussion  above that magnifying eyeglasses require that you hold things closer.  To find the clearest point, with the glasses on, hold the reading material at a ‘normal’ distance of about 16 inches (40cm). Now pull the print closer until it appears the clearest.  This is the focal length of that lens.

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