
Easing Eye Strain with the Right Lenses (2012) - walterbell
http://www.nytimes.com/2012/03/15/technology/personaltech/easing-eye-strain-with-the-right-lenses.html
======
CalChris
I got a little pushback (not a lot) from my optometrist when I first requested
an FD set at laptop distance. However it has made a huge quality of life
difference for me.

I also gave up on progressives and now have two pairs: readers and drivers. My
current correction is insanely good for reading and for driving. In fact, my
opto said it was quite a bit better than 20/20 with no eye strain. Well, there
was some eye strain when I adapted to the new prescription. That lasted about
a month.

So I strongly recommend that you educate yourself (nerd out) about your
choices before going to you optometrist or optician. They can’t educate you
and they need to make a buck.

At this point I just go in and say I want single vision Trivex on Marchon
623s. I'm up in the air on coatings, tints, polarized and photochromic. I
don't need free form given how good my correction is but if you have a
difficult prescription that might be a quality of life thing for you.

You cannot depend on optometrists+opticians to make the right choice for you.
You need to educate yourself on the available choices.

BTW, I think the same can be said for contacts. Know your choices.

~~~
jasode
_> I also gave up on progressives and now have two pairs: readers and
drivers._

Yes, both progressives and high-index lenses suffer from the same problems:
_smaller field-of-vision and higher distortion of peripheral vision_

If I sit with my eyes 36 inches away from a 30-inch screen...

With a single-vision lens, without my head moving at all, my eyes can move
within their sockets to see the bottom corner of screen showing the date &
time, and to the top corner showing the [x] button to close windows. Single-
vision lenses have edge-to-edge clarity.

With progressives or high-index lenses, it requires rotating & tilting my head
to put those corner locations directly in my central field of vision. Imagine
a horse with blinkers[1]. The edges of those lenses are blurrier so you have
to move your head to move the lens' center spot toward the item of interest
for maximum sharpness.

Maximum field-of-vision is the optimal ergonomics of looking at multiple
windows of text on a 30" monitor. Yes, high-index lenses are thinner and more
fashionable but I don't need that when concentrating on programming code and
reading web pages.

 _> You cannot depend on optometrists+opticians to make the right choice for
you. You need to educate yourself on the available choices._

That's why I bought my own set of trial lenses[2]. I can methodically optimize
my computer distance vision without exhausting the patience of my optometrist
repeatedly asking, _" which is better? 1? or 2? (again) 1? or 2?"_. I then go
to Zenni and order the exact diopters I need. (I'm not going to buy a glaucoma
tester so I'll still go to the eye doctor for that.)

I end up with 3 separate pairs of single-purpose glasses: 1 for reading books
~12 inches, 1 for computer distance ~36 inches, and 1 for driving 20+ feet.
Swapping out glasses for each purpose is inconvenient but the larger field-of-
vision makes it worth the hassle.

[1]
[https://en.wikipedia.org/wiki/Blinkers_(horse_tack)](https://en.wikipedia.org/wiki/Blinkers_\(horse_tack\))

[2]
[http://www.ebay.com/sch/i.html?_nkw=trial+lens+set](http://www.ebay.com/sch/i.html?_nkw=trial+lens+set)

~~~
mixmastamyk
Thanks, the same happened to me but had no idea what I was doing. Tried the
bifocal progressives and the top half was fine but bottom was like looking
though coke bottles. Had to move my head constantly to get text centered.
Constant movement and fishbowl effect drove me nuts. Thought they were
defective.

Returned them for one computer set and one driving (closeup fine) and they
work well, but up until now thought they or I did something wrong.

~~~
jasode
_> but bottom was like looking though coke bottles._

Yes, exactly! Many others have the same issues and describe it in similar
ways: _" tunnel vision"_, or _" looking through a pinhole"_

It's very strange that optometrists & opticians don't explicitly explain this
trade-off upfront: the "convenience" of progressive bifocals and the "fashion"
of hi-index lenses will always be blurrier away from the center point than
single vision lenses. If customers were properly educated ahead of time by the
opticians, they wouldn't think progressives and hi-index were "defective". The
lenses are not defective -- it's actually an unavoidable optical tradeoff!
Your eyes just happen to be sensitive to it.

Some people adjust to progressives or high-index lenses just fine. Others
don't. I tried them for 3 weeks as they recommended and never got used to
them.

~~~
mixmastamyk
Right, for me the sensitivity came from moving between monitors.

------
ScottBurson
There's a more subtle issue with high-index plastic lenses and the new RGB LED
monitors: the high dispersion of the plastic interacts badly with the red and
green wavelengths of the RGB LED backlight, to produce a much more severe
color separation effect when you're looking through a part of the lens not
near the optical center. I wrote a blog post about this [0]. For the last
couple of years I have been using lenses made of CR-39, the older, lower-index
plastic (with a correction appropriate for computer work; that's about -5.75
diopters for my eyes), and they work much better.

If your absolute correction is larger than maybe 3 or 4 diopters, and you use
an RGB LED monitor, I recommend looking into this.

[0] [http://scottlburson2.blogspot.com/2016/01/lcd-backlights-
and...](http://scottlburson2.blogspot.com/2016/01/lcd-backlights-and-eyeglass-
lenses.html)

~~~
walterbell
Freeform single vision lenses are marketed as having a larger optical center
and less distortion for strong prescriptions, but they are expensive,
[https://www.2020mag.com/article/premium-free-form-single-
vis...](https://www.2020mag.com/article/premium-free-form-single-vision)

Are the CR-39 lenses noticeably thicker?

Edit: first I’ve heard of wide gamut RGB LED monitors,
[https://pcmonitors.info/articles/the-evolution-of-led-
backli...](https://pcmonitors.info/articles/the-evolution-of-led-
backlights/#RGB_LED_8211_a_rare_breed)

~~~
ScottBurson
The maximum thickness is about 4mm -- very reasonable, given the strength of
the correction. This is with a fairly small round frame (lens width 41mm).

The first RGB LED monitor I ran into was an Apple Cinema Display, several
years ago. I initially didn't understand why I found it so uncomfortable to
use. I think all the iMacs built in the last 7 years or so are RGB, as are all
the Retina MacBook Pros. -- Well, as the article you linked to explains, they
might be GB-r instead (green and blue LEDs with a red phosphor). From a
dispersion perspective, GB-r is just as bad as RGB; so are quantum dots and
the now-obsolete wide-gamut CCFL. All of these wide-gamut technologies will
have much more red-green dispersion than either the old standard CCFLs or
WLED.

I wasn't aware of Freeform; I guess that's because I don't use progressives --
I just switch glasses, or slide them down my nose to adjust focus. But it
seems to be a lens shaping technology, not a lens material.

~~~
walterbell
Hmm, does it apply to iPhone and iPad screens, especially with Apple’s “True
Tone” display? Given the size of the iPhone user base, your blog post should
be better known.

edit: web search did not locate definitive statements about RGB LED in either
iPhone or Macbook retina screens.

~~~
ScottBurson
Well, I'm not certain about past models, but the current MacBook Pro
advertises "Wide color (P3)", referring to the DCI P3 gamut. This obviously
requires a wide-gamut backlight of _some_ kind. I found this [0] blog post
talking about DCI P3 vs. Adobe RGB.

Looks like the iPhone 7 was the first iPhone with a wide gamut [1]. No idea
about the iPad.

[0] [http://www.colourspace.xyz/the-new-apple-imac-and-the-
dci-p3...](http://www.colourspace.xyz/the-new-apple-imac-and-the-
dci-p3-colour-gamut/)

[1]
[https://www.reddit.com/r/apple/comments/5287c3/lets_talk_abo...](https://www.reddit.com/r/apple/comments/5287c3/lets_talk_about_that_new_display_in_iphone_7/)

------
walterbell
There is a fascinating data, robotics, manufacturing, supply chain and retail
story to be written about the optical industry.

The largest lens maker (Essilor) has merged with the largest frame maker
(Luxxotica) and they also own online retailer FramesDirect. A former executive
of Essilor runs a Canadian company that is acquring independent opticians.
Japanese lens makers (Hoya and Seiko) have merged in response.

Essilor, Zeiss and others are asking opticians to spend thousands of dollars
on equipment [1] that measures patient’s eyes for lens personalization. This
data (including auto-refraction [2]) then gets aggregated with optometerist
prescription data (subjective refraction = which is better, 1 or 2), providing
Google captcha-style human input to improve the software algorithms used in
measurement. Opticians are funding their robot replacements.

Today, online retailers like FramesDirect use average values for some fitting
measurements (e.g. pupil/fitting height in frame for optical center of single
vision lens). There are mobile eye measurement apps that take a photo of your
face with a credit-card sized object to adjust for scale, but they are not too
accurate. At some point, self-service [3] optical measurement devices and lens
customization algorithms will enable optical telemedicine globally.

[1] Optical dispensing goes digital, [http://visionmonday.com/article/cover-
story-dispensing-goes-...](http://visionmonday.com/article/cover-story-
dispensing-goes-digital/)

[2] Wavefront aberrometer, [https://www.fastcompany.com/3049271/this-iphone-
accessory-re...](https://www.fastcompany.com/3049271/this-iphone-accessory-
replaces-an-eye-doctors-office)

[3] Vision test with remote opticians,
[http://www.mobihealthnews.com/content/smart-vision-labs-
laun...](http://www.mobihealthnews.com/content/smart-vision-labs-launches-
consumer-facing-smartphone-enabled-vision-exam-telemedicine)

------
superkuh
At my -10 diopter in both eyes there's no winning with multi-monitor setups.
It's a trade-off between chromatic abberation, internal reflection, and edge
distortion.

All the high refractive index lens materials I have tried have terrible abbe
number and so their chromatic abberation is so bad I can't even LCD text out
of the corner of my eye; or read a license plate on a car to the front left of
me. I don't even bother with high index anymore.

But moderate refractive index (and decent abbe number) means my lenses are
more than a centimeter thick at the edges. In addition to being heavy they are
so thick that the nose pad arms don't fit. So the edges of the lenses have to
be carved off. This leads to very bad internal reflections.

I've tried exaggerated spherical curvature in order to minimize thickness
while keeping a good lens material (high abbe) but that tends to distort
(compressing) the image out of the sides the lenses and that leads to nausea.

I wish there were companies out there that would make custom achromatic lens
for eye glasses. Their internal reflections can't be worse than what I have
now.

~~~
ChuckMcM
I was testing point and shoot cameras the other day and one of the things that
impressed me is just how quickly and smoothly they can auto-focus. I found
myself looking around at the world through the viewfinder screen and it
occurred to me that with 400+ ppi LCD displays why have we not yet created a
'visor' which is simply a reproduction of the scene outside but in constant
focus for our eyes (I wear progressive lenses which, with a prism, have
issues). Curve an iphone X screen to make a wrap around screen I think there
is certainly something there.

~~~
crooked-v
The highest-density current VR headsets (at 4K per eye) still have a semi-
noticeable 'screen door' effect from the individual pixels.

~~~
Doxin
You don't need to include a pixel display for autofocus. DSLRs show the real
world projected directly onto a screen at a comfortable focus distance for
example.

------
gxs
PSA:

Grew up pretty poor. One of those people that just got lucky and was never
seriously injured since I didn't have health insurance until I went to
university.

Again, I was one of those people that always struggled to read for extended
periods of time. It never occurred to me that I might need glasses and I
didn't have a single eye exam as a kid.

Fast forward to one of my last semesters. I finally go in for an eye exam and
sure enough, I needed glasses.

After I got the glasses, studying for long periods was effortless (at least by
comparison) and needless to say, my grades improved drastically. For at least
a short period, I felt what it was like to do well in at a really competitive
school.

I really wish that period had been longer, so please, if you're reading this
and you've been putting off an eye exam, go do it today.

------
enrmarc
Off-topic: do you know if there exist glasses that do not touch the nose?

~~~
walterbell
There are "saddle bridge" frames which don't have nose pads:

[http://www.rx-safety.com/frame-only/art-craft-palm-
bay-300-e...](http://www.rx-safety.com/frame-only/art-craft-palm-
bay-300-eyeglasses-palm-bay-300-frame-only.html)

[http://eyeglass.com/stepper-eclectic-9701.html](http://eyeglass.com/stepper-
eclectic-9701.html)

[https://www.ebay.com/sch/Eyeglass-
Frames/180957/i.html?_nkw=...](https://www.ebay.com/sch/Eyeglass-
Frames/180957/i.html?_nkw=saddle+bridge+eyeglasses)

------
cilea
try [https://www.jins.com/](https://www.jins.com/)

I picked up two pairs, one in Taipei and one in Tokyo. The filtered one has
been great so far; I have not experienced any eye strain. What a relief since
I stare at the computer screen for at least 14 hours daily.

Caution: the filtered lens does affect color accuracy a little and makes the
surrounding seems a bit darker.

------
vonnik
Fwiw, I got readers a few years ago, when I was working 12 hour days in front
of a screen. They're weak lenses. When other eyeglass wearers put them on,
they think they're fake. But they make a huge difference for me, just by
diminishing the effort of focusing on a screen to near zero. I don't feel
anywhere near the same eye fatigue.

------
sevenfive
I guess you can't do this at an office, but as a student I just project onto
the wall whenever I work at home.

------
jdavis703
I have tried programming with contacts in (usually when my glasses were
damaged beyond repair or lost). I can barely work for 6 hours before the
contacts dry out, even when using contact lens drops. Does anyone know of tips
for finding contacts that are good for computer use?

~~~
csomar
I'd advise strongly against using contacts. Not only for work but like ever.
Eye drying seems a simple problem until the unfortunate event of corneal
erosion. The risk is higher since you are putting some plastic on top of your
eye. If it is dry, it is as bad as any plastic.

With time, you'll damage the surface of your eye to no repair. Read the
Internet for some real experiences.

~~~
pm90
Is this just FUD? I've been using contacts and doing coding for over a decade
now. I get my annual checkup from the eye doctor. They would know if my eyes
were getting damaged, wouldn't they?

~~~
pragone
Like any intervention to the human body, there are risks. Properly maintained
and adjusted, contacts carry very few risks.

Anecdotally, I've yet to find a pair of glasses that lets me function in the
world as well as contacts. (My eyesight is poor enough that I cannot see the
screen on my phone with both eyes open, as it has to be so close to one eye
that it is too far from the other.) Wearing contacts lets me see the entirety
of my world, not just the portion within the frame of my glasses.

------
fouc
Is anyone familiar with eye minus? I once went to two different optometrists,
and ended up with completely different prescriptions, and only the one that
realized I had a "minus" eye was the one that gave me the best prescription.

~~~
walterbell
This link says there are two numbering systems for cylinders that mean the
same thing: [http://www.usaeyes.org/lasik/faq/read-eyeglasses-contacts-
pr...](http://www.usaeyes.org/lasik/faq/read-eyeglasses-contacts-
prescription.htm#minus)

Mixing up a Minus (near-sighted) vs Plus (far-sighted) value for sphere would
be unusual.

------
MicroBerto
I find life to be MUCH better when I have a 144Hz screen running.

But then I bought a laptop with no capable video card. I'll be going back to a
PC with appropriate 144Hz capable graphics very shortly for my main machine.
It's like night and day on my eyes.

------
morcutt
I've been wearing Felix computer glasses for the past ~2 weeks. I was really
surprised to see the difference. My eyes were so strained all the time
previously and that feeling has almost completely gone away.

------
nextos
I do have eye floaters since last year, which are quite annoying. Anyone has
any experience on preventing further problems?

My OCT scans are fine, so it's a bit puzzling. Floaters came at the same time
as tinnitus.

~~~
dkobryn
This is fascinating. I have had eye floaters and tinnitus for many years. Both
problems have been frustratingly intermittent for me. But over time, I have
gotten them under control. The answer for me was food. If I had a burst of eye
floaters or tinnitus I would ask myself “what have I eaten recently” and make
note of it. Soon patterns emerged, for example, beer caused really bad eye
floaters and candy would set off my tinnitus. So I ate less of anything
correlated with my symptoms. Not a sexy solution(especially if you like beer),
but has worked wonders for me in the long run. Good luck.

~~~
nextos
Very interesting, thanks for commenting.

I've seen papers where floaters and tinnitus are associated to lyme disease.
It can also be linked to thyroid issues that have led to autoimmunity.
Autoimmunity can be connected to food.

The weeks prior to my floater onset, I had really bad migraines and pain
"behind" my eyes, close to the nose.

My floaters are permanent. Most seem to be. I also get occasional mild
flashes, which are probably caused by little changes in pressure within
vitreous regions close to my retina.

------
Stratoscope
I highly recommend the system I've used for the last 20 years: two pairs of
prescription glasses, one for computer use and the other for general use.

The computer glasses are single vision lenses (not progressive or bi/trifocal)
corrected for the distance to my laptop screen, about 20". This is _not_ a
"reading" prescription, which would be more like 16" and not suitable for
computer use. I bring my ThinkPad to the optometrist to check the prescription
while I'm there. They have test lenses they can combine to show you what the
final prescription will look like.

At my home office I use an external 24" 4K monitor in portrait mode in
addition to the ThinkPad's high-DPI display. The monitor is mounted on an
Amazon Basics adjustable arm (made by Ergotron), so I can easily position it
at the same 20" distance from my eyes. This is a great combination with
documentation on the portrait monitor and code on the ThinkPad display.

The general use glasses are progressive lenses with magnetic clip-on
sunglasses. I don't like the clip-on sunglasses that have actual clips, even
though you can get them for any kind of glasses. The magnetics are much nicer,
although there aren't too many choices available. Flexon still makes one set.

Since I always wear shirts with pockets, this is really handy. I can use the
clip-ons when outside or driving, and then when I walk indoors I simply snap
them off and put them in my pocket. They don't need to go in a case when I do
this; the clip-ons go in my pocket with the front facing out so I hardly
notice they are there, and a cotton shirt provides ample protection.

I like progressives _much_ better than bi/trifocals, because there are not
just two or three discrete focus distances, but an entire range from infinity
down to much closer than the 20" computer glasses. They are fine for reading
on a phone screen or a Kindle too, since you don't need such a large area in
focus. They are also great for photography; you can have both the camera's
display and the subject in focus at the same time.

There is really no need for a separate pair of "reading" glasses, since the
computer lenses and progressives cover all the bases.

I do not recommend progressives (nor bi/trifocals) for computer use. They are
a recipe for eye and neck strain as you tilt your head back and look down
through the bottom part of the lens. When I see people do this I cringe. It's
OK for a few minutes but not for any longer term use.

I do occasionally use the progressives when I'm looking over someone's
shoulder at their screen. It's probably going to be a lot farther away than my
20" laptop distance, so I can't really use the computer glasses.

I don't recommend the trendy-looking lenses that have very little height. They
don't work well for computer use, since they may not cover the entire screen
at the time, and they are terrible as progressives since the compress the
focus area so much. How you _see_ is more important than how you _look_.

I definitely recommend getting your eyes checked even if you are much younger
than me. You may think you are doing OK, just like I thought for years. But
when I finally realized I wasn't seeing my computer screen as clearly as I
should, and I visited a good optometrist with my laptop and tried their
temporary lenses, I was amazed by the difference.

Most people's eyes change fairly rapidly during their 40's. You may need a new
prescription every year or two. After that the changes slow down and you can
probably use the same prescription a bit longer. But there still are changes
over time, and it's a good idea to get regular eye exams to check for other
problems.

This combination of prescription computer lenses and progressives with
magnetic clip-ons continues to serve me well at the age of 65. With the
computer prescription, I can see every pixel on a medium-DPI display, so it
has spoiled me and I only like high-DPI displays now.

------
babaganoosh89
I’d recommend anyone with eye strain problems consider Lasik. I used to have
eyestrain multiple times a week before lasik, and now I get eyestrain maybe
once or twice a year.

------
abalashov
I have a fairly large power difference between my eyes; my right eye is nearly
perfect (maybe -0.5 or so) but my left eye is -2.75. This has been the case
since 7th grade or so.

At the time, I was prescribed glasses and advised to wear them all the time.
But, of course, since I didn't need them in order to function (because I had a
good right eye), I didn't. Moreover, I grew up programming and spent much of
my adolescence in front of a screen with uncorrected vision. I was warned that
there might be problems due to this later, and ignored them, since everything
seemed fine. What's more, my glasses' focal point was unquestionably long-
distance and simply added fatigue to computer use that was not present without
them.

I first started experiencing occasional bizarre headaches in 2010, one of
which landed me in the ER because it was so bad. At the time it was treated as
an atypical migraine. But things really came to a crisis point in spring and
summer 2012. I started getting brief episodes of vertigo after more than ten
minutes at a screen. The problem was particularly bad when going from near to
far focus or vice versa; I'd get this "need for speed" effect where it felt
like the world was topsy-turvy, rushing past me. It was very disturbing for a
person who is deeply uncomfortable with not feeling in control. Anyway, I
couldn't work, and spent the entire summer doing the one thing that seemed
tolerable -- watching TV shows and movies at close range. I did a little bit
of travelling and had an absolutely miserable time, compounded by the dryness
of the places I visited. The economic and quality of life impact could not be
overstated. I was miserable, anxious, and unproductive. I was lucky to be
self-employed and somewhat flexible in how I went about working, but getting
through even ten minutes of e-mail was a struggle some days.

Lots of misdiagnoses and rabbit holes along the way; migraines (of which I had
no history), sinus problems, allergies, etc. I took nasal steroids, did this,
did that.

An optometrist prescribed me near-distance computer glasses alongside my long-
distance ones, and this did not immediately solve the problem. I struggled
with such symptoms for another year or so before the problem was anything like
resolved. Even so, I depend on having two pairs of glasses and switching among
them scrupulously depending on what I am doing. I can get by with long-
distance glasses for a little while when doing computer work, but it's
ultimately too straining. The most dangerous of all is no glasses: my problems
come back quite quickly if I do that.

That's what happens when you ignore computer vision issues.

Edit: I've also found that I do better with a single large monitor than two
medium to large ones.

~~~
ruricolist
I have anisometropia even more extreme than yours. I wonder, have you ever
tried contacts? For anisometropia, the closer the prescription is to the eyes,
the better. I choose to wear glasses now, but I still have to go out of my way
to find small enough frames (unfortunately out of fashion) that the lenses sit
close enough to my eyes that the images converge.

~~~
abalashov
I didn't know that, but I have considered contacts for cosmetic reasons.
However, they seem like an awful lot of hassle compared to glasses.

Another question: wouldn't the contacts have to be complex/progressive lenses
of some kind? Clearly, I need two different prescriptions—one for computer
work, one for everything else. Does staring out a bottom or top portion of a
contact lens pose any difficulty beyond what one finds with progressive lenses
in normal glasses?

~~~
ruricolist
I'm not an optometrist, and I haven't worn contacts in years. All I can tell
you is that they weren't nearly as much of a hassle as people make them out to
be. I just have strong, but not vision related, reasons to prefer glasses.

