Good question, haven't visited the optometrist since I was a child for casual checking. Just tried and I'm able to read text with light Arial font size 11 in a

Good question, haven't visited the optometrist since I was a child for casual checking. Just tried and I'm able to read text with light Arial font size 11 in a 15" monitor 1.4m apart, if that provides any clue. Good eyesight at night. Started using computers when about 10yo. Started feeling eye pain (quick needle in the eye kind of pain) since about 30 years ago, and use the technique since then, the pain goes for a few months, and maybe I've had 3 eyestrain crisis in those 30 years, in which I had to apply the method once or twice per day for 1 or 2 weeks then got well for months. I don't know of anyone else using it.