I have just returned from Camp Perry, had a great time and made some good friends from North Carolina, Iowa and Illinois who had neighboring huts. The revolver matches were the most fun for me as well as the CMP EIC ball matches. After talking with a number of shooters, I've come to the conclusion that many shoot iron sights only when they come to Camp Perry. Because of the infrequent use of iron sights, the need for the exact prescription was not important for many shooters. This was not the case for those who routinely shoot iron sights.
Whichever the case, I would like to make a recommendation for shooters to keep all of their old eyeglasses even though the prescription may have changed. The logic behind this thought is that as we age, we will find that one pair of eyeglasses will no longer serve all our visual needs. Depending upon the changes, older prescription lenses may provide the exact focus for specific tasks such as with our iron sight guns.
As we age, those of us in our 50's, 60's and beyond will develop signs of crystalline lens opacification (various forms of cataracts). This may cause our eyes to become more nearsighted or less farsighted. The vitreous humor, the gelatinous material inside the globe of the eye, will become less dense and will cause our eyes to become less nearsighted or more farsighted. Along with these physiological changes, we may have prescription lenses that may have changed 0.50, 0.75 or 1.00 diopters. Guess what? The old eyeglasses you were about to donate may now be your perfect iron sight shooting glasses. You might have heard old grandpa say, "I see better with my 20 year old eyeglasses!" Contrary to misleading popular belief, you won't ruin your eyes by using older eyeglasses.
Here is an example to illustrate my point. A shooter at age 39 has a prescription of -3.00 diopter lens for the shooting eye. At age 49 and now presbyopic, the same shooter has become more nearsighted and needs a -3.50 diopter lens. By using the older Rx for the iron sights, the shooter is essentially using a +0.50 lens over the latest distance prescription. This may very well be the same lens I would have prescribed for this shooter using the iron sight pistol.
If changes in the prescription eyeglasses are small, you might try to see if the red dot becomes clearer with older eyeglasses. We had discussed that the red dot may not be focused at the same distance as the bull. As long as the older eyewear is in a safe condition and the changes happen to be in the correct direction and magnitude, you may be in for a pleasant surprise. This won't work for everyone, but it will for some.
I would like to make a suggestion for all shooters to ask for a copy of their eyeglass prescription(s) after the exam. Also, bring your older eyeglasses for the doctor to inspect and to see if they would be compatible as shooting glasses. The vision guide, "Bullseye Shooters' Guide for the Eyecare Professional," may be helpful for your eye doctors because many eye care professionals are not aware of the shooters' visual needs. Keep in mind that routine eye examinations are still important.
Here's a summary:
For myopic (nearsighted) eyes: If you have become more nearsighted with aging, try your older eyeglasses which will have a lesser amount of minus power in the prescription.
For hyperopic (farsighted) eyes: If you have become less farsighted with aging, try your older eyeglasses which will have a greater amount of plus power in the prescription.
Good Vision and Good Shooting To All,
Norman H. Wong, O.D.