Ask HN: Do your eyes bug you even though your prescription is "correct"?

The solution for me to eliminate headaches when working at computer screens was getting an extra set of intermediate distance glasses specifically for computer work. The "computer screen distance" of 3 ft is in between book-reading distance of 1 feet and driving distance 20'+ feet. I also avoid progressive lenses or high-index lenses for computer work. I commented about how arrived at this solution previously: https://news.ycombinator.com/item?id=15375221

Reading glasses work fine when the screen is very close to your face such as a laptop screen. However if it's a separate monitor that's ~30 inches away, reading glasses are slightly blurry which can lead to eyestrain and headaches.

https://www.warbyparker.com/learn/wp-content/uploads/2023/04...

Look into it if you suspect it's a contributor to headaches: https://www.google.com/search?q=computer+glasses+%22intermed...

> I also avoid […] high-index lenses for computer work.

Yes! You're the first to mention this.

It's not refractive index itself that's the problem, it's dispersion (roughly, the degree to which refractive index varies across the visual spectrum, described by ‘Abbe number’). We've all seen pictures of a prism splitting a beam of white light into a rainbow — for visual purposes, the less split the better.

Higher-index materials tend to have poorer dispersion, but especially in the mid-range 1.6ish, there are wide variations in quality at the same index. Glass tends to be best, if your prescription is light enough that you can handle the weight. Polycarbonate and acrylic are awful. MR-8 is in the middle, and what I've settled on for recent computer glasses.

This worked for me as well. I just asked the eye doctor for something that would work just past my out stretched finger tips which is where my monitor lives.

What kills me is going into the office where I am switching between glasses. Different rooms with different Zoom screens. At home is much nicer where I just have one big monitor to watch.

I take my glasses off to read my phone most of the time. Technically my primary glasses are progressives but it is nicer to take them off.

Same - the funny thing is that right now my 3-foot prescription is zero (plus a bunch of astigmatic correction). Apparently my mortal frame has accepted its purpose.

I use a 60" TV and get farther from it. Stopped needing glasses.

> I take my glasses off to read my phone most of the time. Technically my primary glasses are progressives but it is nicer to take them off.

Same. I wear progressive lenses and I feel like they do fine as far as being able to read the text on my phone or for reading a book. But I tend to take off my glasses anyway to do these things. I'm not entirely sure why this is since I seem to be able to read the text fine with the glasses. My hypothesis is that I like being closer to the text so that it fills up more of my visual field which helps me mentally focus on the text better.

I'm in a similar boat.

I'm nearsighted and don't need glasses to see my computer screen clearly at all. But nevertheless I started getting headaches from eye strain.

Went to the optometrist, got a pair of glasses just to reduce eye strain at screen distance. Zero difference in sharpness, but I can work all day long with zero eye fatigue.

I use different corrections for laptop at about 18-28" and reading in an armchair at 15-23" -ish. It's really not a big difference in distance!! - and still very noticeable.

It's not for avoiding outright headaches (I don't get vision headaches) but it's clearly more comfortable. It's quite possible that what's pleasant is in part the change of pace - but it is also better adapted for sharpness.

I don't wear glasses (yet) but came to this thread to ask what effect this would have. (I do a good chunk of my computing on a 65" display at 2m.)

Same here: my reading glasses are great for reading, but when I work with computers, my screen is halfway between wrist and knuckles on an extended arm. That's too far for reading glasses. So I got a set of intermediates and things are great. I use them for working with a screen or a laptop, while I use the reading glasses for reading, soldering and other work where the objects I'm looking at are within 40cm of my eyes.

> book-reading distance of 1 feet

12 inches?

that's way too close

Can’t find the message you’re replying to but I think you’re imagining the person sitting up.

Imagine them lying down or propped up on their elbows with the book on the floor. Then that distance seems about right.

I also regularly look farther away out the window and back inside. That kept me going back and forth on needing glasses for years, but when I set up the monitor, no more need for glasses. (I'm 65)

What sort of prescription is right for Oculus?

Hear, hear!

Here's a good way to test your glass's refraction index. On your desktop find a small red icon with something white in the center. Stare directly at it. Now turn your head until the icon is at the edge of your vision. If your lenses are cheap polycarbonate, the white part of the icon will appear to move towards the edge of the icon or even out of it.

Most non-cheapo glasses today in the US use Trivex. It's a polymer, not glass, but its Abbe number is 43, which is perfectly adequate.

Crown glass, with its Abbe number of 59, is superior, but the eyeball can discern differences only up to 45-50, so most of Crown glass's improvement over Trivex is imperceptible.

This is partly why it's not offered in glasses (again, in the US, at least according to my optometrist). It is also twice as heavy, shatters (polymers like Trivex don't), and scratches more easily.

I can second this, after getting PRK I ended up slightly farsighted after being majorly nearsighted, I did a intermediate pupillary distance between my distance PD and near PD and its great for how I use a computer which is 99% of reading I do.

That's way too close for books or screens. Long term it can cause myopia.

Among non-glass options, CR-39 is a good choice for computer glasses with prescriptions weaker than -5:

  - high (58) Abbe number
  - thick (1.5 index)
  - cheapest

Thickness and weight can be mitigated with a smaller frame, e.g. vintage options.

Actually buying CR-39 lens might require solving a dark pattern maze of online or offline options, since the cost is so low.

A fun fact I learned recently, after years of casually skimming color science, is that our eyes cannot focus the entire visual spectrum at once.

That’s why our cone response to the spectrum looks like https://en.m.wikipedia.org/wiki/Cone_cell#/media/File%3ACone... instead of having cleanly segregated red vs. green responses. If it was segregated, we could only focus on red or green but not both. By having a heavy overlap, we can get a sharp focus on yellow. And, the visual system makes the full spectrum work by deriving the red vs. green concepts from the difference between the two cone responses. Blue focus is accepted as a necessary sacrifice.

I only need a basic 1.0 reading prescription but I have about 5 pairs of glasses. I'm hyper-sensitive to even the slightest deviation in prescription.

Currently wearing, to look at arms-length monitor screen, add +1.0. Will move out to the porch to read and switch to add +1.5. Will come back to cook and switch to my basic prescription.

I must put on and take off 300 pairs of glasses a day. But I don't care. I can't do anything else.

One problem I have (well, one of many these days, including some double vision, sigh) is that I'm very far sighted in one eye, and near sighted in the other, so one lens is barely anything, and the other is a coke bottle.

I thought this had been debunked as the cause of myopia?

(Or am I totally misremembering something...)

That makes a lot of sense. I've heard of people using computer-specific prescriptions, but I never really thought about how much difference that intermediate distance can make. I wonder how many cases of "mystery" eye strain are just from using the wrong focal range all day

It's not just about the material. It's also about how the lens is made. For me, choosing "freeform" over "aspheric" was night and day.

I do the same. In fact I usually just wear the intermediate distance glasses all the time around the house, and only switch to my primary glasses when I leave the house. Considering I work from home that can mean that I wear my intermediate glasses almost all day long most days.

That almost seems to reduce eyestrain as well, at least for me, as they're still good enough to see everything (I can't read text across the room but I can halfway across the room), just not without some light blur on things, and I seem to have trained my brain to stop trying to focus on things, just let it stay in the blur (at least while I have my intermediate glasses on), and that seems to relax my eyes more.

But the intermediate glasses are super clear for when I'm on the computer, which is a good chunk of the day and where I really need to see nice and sharp, as I'm manipulating things with pixel precision at times (game ui, web ui, board game graphic design).

How do you do with driving and seeing smaller things on your automobile dashboard? I'm up around 7 diopters nearsighted so maybe it depends on the range of needed focusing.

You can get specific insets for the headsets from places like VR Optician. I’ve had some made with my normal prescription and they work perfectly. The people running VR Optician are actual opticians so you can also ask them if any correction factor would be needed for your particular situation.

A few years ago an optician convinced me to get some fancy 1.67 index lenses, but I couldn't deal with the chromatic abrasion. The text at the peripheral parts of my monitor were clearly split into their RGB components. For frontend work it was impossible, as I couldn't tell if something was not aligned or it was just the chromatic abrasion.

Now I always go for the thickest lenses (which are also usually the cheapest) for this reason. My prescription is -3.75, and there isn't any noticeable difference with thinner lenses.

https://www.selectspecs.com/ if you are in Europe. I've been using them for years.

I have a very weird situation where my right eye was fine but my left, for reasons unknown, has a thicker lens. This can be happen with cataracts but I'm just under 50 and have zero clouding. The eye doctor said it's not myopia in the "usual" sense but the end result is the same: myopia prescription lens.

Thing is, I ignored it for about 10 years and my brain simply ignored whatever signal was coming from that eye. I'd look at things and see no blurring unless I closed my right eye. However, at a certain crossover distance my brain "switches over" because my left eye has amazing close vision and my right eye doesn't. I can actually feel it when this happens, like a physical sensation. No headaches, but it is "odd".

Anyway, I decided to get glasses, and it turns out I need two different prescriptions. One is close up (not longsightedness, it is still a myopia lens). The other is for 1m-∞

chromatic aberration

https://en.wiktionary.org/wiki/aberration#Noun

All the high index lens materials suffer from chromatic aberration.

The lens material you've now chosen actually has the best optical properties out of all the plastic lens materials. Its only downside is that the refractive index is only 1.5 which does mean they will be a little bit thicker than the high index ones.

You could also try a material called Trivex which also has low chromatic aberration while being a little thinner than the material you are using which is called CR-39

You could also try Trivex instead of MR-8. Lens thickness should be similar but it has a higher ABBE value.

Where are you ordering glasses from that you can make selections like this?

I’d love to speak with you - your experience is right in my target zone to research. If interested ping me at jbornhorst [at] gmail.com

My indoor (non Transitions™) multifocus² glasses are CR-39¹.

I'd used the same material for my outdoor/sports/driving frames but it's higher density caused them to slide down my nose during activity so the next pair I opted for Trivex.

--

¹–CR-39 requires full frame spectacles, as drilling holes is verboten.

²–Shamir Autograph III, awesome & highly recommended.

A myopic prescription can actually be good for seeing things close up but not in the distance- explains why you’re able to see close up with that eye OK

Firmoo for example. Probably a local optician should also be able to make this choice.

I got a pair of these just before Christmas and they've really helped - I tried "occupational lenses" which are a strange bifocal with a central focus of 3ft and then outwards it changes to the reading prescription, did not work with how I use the display in that my head is usually fixed and I move my eyes.

The intermediate distance lenses are great and my headaches have vastly reduced - because they were specific for VDU, my work paid for a portion of them.

>The solution for me to eliminate headaches when working at computer screens was getting an extra set of intermediate distance glasses specifically for computer work.

My wife is getting bifocals for basically this same reason.

I don't know which type of glass my glasses have, but I know I had to pay a ton for it, because the cheaper sort can't handle my prescription without being really thick and/or heavy. But as someone that actually wears my glasses all the time and not just randomly, it's worth the extra expense.

>instead of having cleanly segregated red vs. green responses.

I suppose that's why r/g colorblindness is so common.

Interesting, is the lens ultra high-index? How's refraction? As far as I'm aware, high-index, as the index becomes higher, generally will have a progressively worse Abbe number.