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  #23  
Old 01-16-2020, 02:24 PM
jjfitch jjfitch is offline
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Join Date: Apr 2007
Location: Pacific Northwest
Posts: 6,294
Jayhawk:

From Dr. Wong,

"Normally, the best lens for the red-dot scope viewing will be the best distance prescription. Demonstrate this lens while the patient looks at the red dot while holding out the scope. Because the red dot in the scope is not focused at "optical infinity" (it is closer), try a +0.12 or a +0.25 diopter lens over the best distance prescription to see if the dot becomes even clearer. If possible, judgment would be best if the patient can view at a distance greater than the standard 20 feet and with outdoor lighting. If the dot is distorted, use the phoropter once again to verify cylindrical power and axis as the patient holds the pistol (or scope only) in front of the phoropter. Final results should be demonstrated with trial lenses. If the red dot never becomes clear and round after all lens possibilities have been demonstrated, then a careful determination of ocular health involvement needs to be assessed. "

Almost 25 years ago I was having fits with front sight focus and corrective lenses. Dr. Wong's advice has always been right on. I remembered his advice to be sure to specify the exact depth of field when getting a prescription do to the variations in laboratory methods for general purpose vs. shooters.

In my above post #21 I think I was trying to articulate Dr. Wong's advice but in less technical terms. But as usual you saved the day by providing excellant reference material.

If I was getting distortion I would want to take the above information provided by Dr. Wong with me to my "Eye Doc" so he would know what shooter's need for lens correction with red dot sights (optic sights).

All the best in 2020,
__________________
John, Retired LEO, CA POST Certified Firearms Instructor, NRA Endmt., NRA Instructor, NRA RSO, Blue Lives Matter
Gun Control: Acquire target, align sights, press trigger, only after you have identified your target and what is beyond it and made the decision to shoot!

Last edited by jjfitch; 01-16-2020 at 02:32 PM.
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