Comment by walterbell | Hacker News Reader

Comment by walterbell | Hacker News Reader

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disclaimer: not medical advice, please consult opthalmologist

If you are nearsighted and wear your full distance prescription for extended near (computer/reading) work, there is some chance that your eye will adapt to the most dominant distance, eventually requiring a stronger prescription for distance/driving. Rinse/repeat = ever worsening glasses for some people.

To avoid this problem, ask your optometerist for a separate (weaker) prescription for computer glasses. You can get a ballpark idea from http://computerglassesrx.com. Glasses are cheap these days, e.g. online from Zenni for less than $50.

Lasik carves a lens onto your eyes. If that lens strength is your distance prescription, the same issue exists as with glasses. To reduce close-up strain on your eyes, you can use plus lenses for close-up work, which reduces the lasik/contacts "minus" prescription for near distances. Look at the calculator above for an estimate, but consult an eye doctor, as there are variables like age/presbyopia/convergence.

Previous HN thread on Lasik: https://news.ycombinator.com/item?id=9941566

Non-mainstream discussion of plus lens therapy: http://forum.gettingstronger.org/index.php?topic=1115.0

I can second the advice about the 2nd set of glasses.

Last time I upgraded my prescription I asked my optometrist about working in from of a computer all day, and he said "If you can see the screen without wearing any glasses, do that. Otherwise use your old ones (with the less powerful lenses)."

Since I've been doing that, my eyes have felt a bit better. Maybe I could get away with an even weaker set, but I haven't really looked into it.

Since getting some computer glasses my eyes have gone from deteriorating every year to getting slightly better. Might be a coincidence but I suspect not. Next time I'm in Asia I'm going to get an even weaker pair and see if my eyes can keep improving.

Cliff Hayes successfully went down that unsanctioned road, he published some videos [1] and a PDF [2]. We need more scientific studies [3] to figure out why undercorrection works for some people.

When it works, the key seems to be relaxing the eyes and surrounding muscles while viewing objects at a distance which causes just enough blur. Within a minute or two, the brain's visual cortex figures out a "software compensation" for the signal coming from the eye, which lets the eye stay relaxed instead of straining to focus. More info on Vision Therapy is available from behavioral opthalmologists, but it takes time, motivation and may not be covered by insurance.

[1] https://youtube.com/user/cliffgnu

[2] https://drive.google.com/file/d/0B5REdzibAJQ4VFJuWnZCU3dLcHc...

[3] https://dspace.mit.edu/openaccess-disseminate/1721.1/105363

This is purely anecdotal. I have a bad astigmatism. I tend to not wear glasses until I have to. In the garden I don't bother. And oddly, when I do use my glasses everything becomes too much. In my mind scenery becomes unpleasantly cluttered/dirty. It's quite horrible. I prefer the soft focus - but can't read the laptop, watch TV without.

If your astigmatism (cylinder) and/or spherical diopter numbers are very high, your glasses may have significant distortion when looking through any point other than the optical center of the lens, e.g. for peripheral vision. Have you compared contacts with glasses? They provide a much wider field of view.

If you like soft focus, you can try on different drugstore reading glasses (e.g. +0.50) over your normal glasses, to find a reduced strength which lets you see at the desired distance without super-duper-sharp edges. Then ask your optometrist to provide you with a reduced prescription for non-driving or near work tasks. Otherwise, they will prescribe driving-strength glasses to avoid legal liability.

Interesting, my prescription was out of range for contact lenses when last explored. It might be worth me getting something as best as they can get if the contact effect is beneficial.

If your prescription is out of range for contacts, it means it is very weak, so there shouldn't be much distortion in glasses, hence you won't see much difference with contacts.

Easiest would be to find a friendly optometrist who will put your astigmatism prescription into a trial frame, then let you self-adjust the cylinder and axis values until you find your desired blend of clarity and softness at your target distance. They can also advise on the safety of using that prescription vs using no glasses.

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