Re:Ask HN: How do you prevent eyestrain with daily computer ...
by benibela on Sunday December 13, 2020 @05:22PM
(#25410989)
I have astigmatism and nearsightedness
And I did what burkemw3 did: Astigmatism-correcting glasses only.
But it was very difficult. I went to an optician to buy them, and they told me, I would not need them, so they won't sell them to me. When I am nearsighted, all my glasses should correct nearsightedness fully.
And to make it worse, they were not able to measure my astigmatism. The first one I went to measured 1.5 D cylinder and gave me such glasses, but that was a little blurry, so I went to several others and measured them and then said you have 20/20 vision, so everything is perfect. I finally found one who measured my eyes from scratch without taking the value of the old glasses and then he found 2.75 D cylinder, leading to a 30% better vision than 20/20.
However, some of the opticians had wavefront eye laser scanner. That is a really advanced method to measure directly how the eye affects lightwaves rather than trying different lenses. The devices measured that I actually need a 3.6D cylinder. But the opticians always discarded that measurement, because it was not possible that I had 20/20 vision if my glasses are two diopter too weak.
Anyways, since they did not sell me computer glasses, I bought them online, and just put zero for spherical value of the prescription. Although there seems to be something wrong, since I am always seeing sharper on one eye than the other. I also tried buying a stronger cylinder online to check it out, but that was not possible since the online sites did not sell any cylinder stronger than three diopter.
And I did what burkemw3 did: Astigmatism-correcting glasses only.
But it was very difficult. I went to an optician to buy them, and they told me, I would not need them, so they won't sell them to me. When I am nearsighted, all my glasses should correct nearsightedness fully.
And to make it worse, they were not able to measure my astigmatism. The first one I went to measured 1.5 D cylinder and gave me such glasses, but that was a little blurry, so I went to several others and measured them and then said you have 20/20 vision, so everything is perfect. I finally found one who measured my eyes from scratch without taking the value of the old glasses and then he found 2.75 D cylinder, leading to a 30% better vision than 20/20.
However, some of the opticians had wavefront eye laser scanner. That is a really advanced method to measure directly how the eye affects lightwaves rather than trying different lenses. The devices measured that I actually need a 3.6D cylinder. But the opticians always discarded that measurement, because it was not possible that I had 20/20 vision if my glasses are two diopter too weak.
Anyways, since they did not sell me computer glasses, I bought them online, and just put zero for spherical value of the prescription. Although there seems to be something wrong, since I am always seeing sharper on one eye than the other. I also tried buying a stronger cylinder online to check it out, but that was not possible since the online sites did not sell any cylinder stronger than three diopter.