People who reach middle age often develop "long sight" due to which they are unable to focus on objects that are close by (and need reading glasses) while they are able to see distant objects clearly. For shooters. this means that the rear sight and fore sight are blurred while the target is seen clearly.
One hurdle that I personally faced while shooting (especially in the prone position, but also while standing) is that wneh one's head is bent down to sight the target, one is either looking above the frame of one's spectacles or the frame is obstructing vision since glasses, especially glassses for people with long sight are not designed for close focus through the upper part of the lens.
What I did was to buy a cheap (Chinese

) pair of reading glasses - usually available for less than Rs 200 at opticians. A power of 1 or 1.25 is just enough to get the rear sight and fore sight into focus without blurring the target. I used a pair of pliers to bend the ear rests upwards, and I did the same for the nose clips so that the glasses could be worn upside down.
Here is a comparison of a normal pair and the modified "shooting" glasses
mod-glass.jpg
This is what the modified glasses do to the line of vision if worn while shooting. The glasses are worn "upside down" and rest comfortably on the nose and ears.
mod-glass-line.jpg
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