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Ask Slashdot: Are Progressive Glasses a Mistake For Computer Users?
An anonymous reader writes I'm a daily, all-day computer user and use two 19-inch monitors for my work. I'm at the age now where I need reading glasses, and my optometrist steered me to progressive lenses. I don't need any correction for distance, only reading. I'm trying very hard to get used to them, but I hate them. The focal point seems to be about 1 inch big, with everything around that blurry. Reading books on my iPad is a struggle; I have to turn my head side to side simply to keep the line of text in focus, and when I do that, the page warps and flow in a dizzying manner. I don't think reading should be like watching a tennis match. And using my two monitors at work? Hopeless and frustrating! Has anybody here who uses either very large or multiple computer monitors figured out how to comfortably use progressive glasses? Or are they simply inappropriate for this kind of use?
I suspect you have a very high correction. My corrections are +1.50 and +1.75 or thereabouts, and I have had progressive lenses for years. They work fine without the problems you describe. My wife, however, has corrections of around +8.0 in both eyes and could never make a go of progressive lenses for the reasons you state. Eventually, she decided on Lasik surgery, which has unfortunately not really gone well -- we're over six months out from the initial surgery and she still needs glasses. She's one of the 1% or so for whom it does not work on the first try.
Good luck.
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I have the same problem as the OP with age related astigmatism and my optometrist suggested progressive lenses. One thing my optometrist was clear to point out was the limitations of the cheaper progressive lenses, where the area in focus was narrow. More expensive lenses offered a much wider field of view, which is what I purchased, but they weren't cheap at $800. The only downside to the lenses I bought was significant barrel distortion on the extreme edge of the lens.
For general use I love my progressives as I can drive and read with the same pair of glasses. I do keep several pairs of general reading glasses around for reading and computer use.
This site has a great comparison, at least for Nikon lenses:
http://www.nikoneyes.com/produ...
With proper, prescription lenses, the lenses are designed to accommodate your eyes. That means you may have a +0 (non-corrective) and a +0.25 or a +1.75 and +1.25. Interpupiary distance is also important: poorly-centered lenses are the cause of painful headaches. All in all, prescription lenses, even prescription reading glasses, are vastly superior to off-the-shelf bifocals.
I got transition lenses in a single-focus design, and I hate them. They're fantastic, except when they get dirty every 5 minutes, get a burrito shoved into them (they're further from my face than my eyes are), or cause my eyes to water. I plan to have contact lenses fitted; this will be more annoying at first, but will have the incredible advantage of being cleaned every 11 seconds, as well as providing a larger field of view. Silicone soft lenses transmit enough oxygen to safely use them for 30 days straight, rather than removing them at night time; I can elect to remove them at night if desired, but I'll still minimize the risk of complications by providing oxygen permeability similar to not having lenses.
Optometry is hard. Some of us are decisionary maximizers, so it's hard even being the patient!
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Coke-bottes: think lenses generally used by far-sighted people who need glasses to see in focus up close.
Bi-focals: have a half-circle shaped area in the bottom of each lens at a different power (for reading) while the rest of the lens is set for regular viewing
Progressive: has the regular lens gradually change to reading power so you don't have the tell-tale line (and power jump) associated with bi-focals.
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Don't use progressives or bi-focals. Do this:
Take a tape measure and measure the exact distance to your monitors when working.
Go to an optometrist and get a written prescription for that exact distance (bring the tape measure with you*) including the "PD", pupillary distance, at that range. Do not buy the glasses from them.
Go to Zenni Optical ...and order some $6.95, single vision prescription glasses from them that fit your PD size.
http://www.zennioptical.com/u6...
Add the standard anti-reflective coating for $4.95
For about $12 you have custom computer glasses.
* Yes, I actually do this. And, yes; I'm a nerd.
Yeah, but contact lenses won't work for close-up stuff. Contacts are for when your eyes are the wrong shape; the reason older people can't read well is because their intraocular lenses are no longer flexible and they can't focus on close-up things. Contacts won't help with that; if you put contacts in to correct that, you won't be able to see anything farther than arms' reach. And unlike bifocals/progressive-lens glasses, you can't really orient contacts so that a region with different correction is at the bottom.
Reading glasses, those off-the-shelf from a rack with a positive prescription, are not for those that need prescription glasses. They are for older individuals who still can focus at distance, but who have lost the muscles and lens plasticity to focus their eyes on closer objects.
The eye becomes able to focus on a smaller range of distances in older age, and for a person with good vision who has not needed prescription glasses, this might mean they can focus from infinity to 100 cm instead of infinity to 10 cm of their youth, making reading a book difficult.
The majority of those needing prescription glasses are myopic, or short-sighted, meaning that they can focus well on close objects, but cannot bring far objects into focus with their eye's lens. They will never be able to see far objects such as the stars clearly without optical correction. Unfortunately, after correcting the vision with prescription glasses, the same problem also occurs in older age, individuals can no longer bring closer objects into focus while wearing prescription glasses.
Simply taking the glasses off allows for seeing close objects again, but is suboptimal. First, the prescription glasses likely also correct for astigmatism, another type of distortion in the eye's lens or shape. Secondly, uncorrected vision in people that are quite myopic, such as myself at over -4, means that I can read a book when held a bit closer than would seem normal, but cannot focus on 2x24" monitors when they are 0.5m away, computer monitors are too far away to see. I would travel the world in a bubble where only things 15" or closer can be seen without glasses.
When the eye's lens becomes less plastic in older age, this may mean that the 0.5m monitor can neither be seen cleary with traditional prescription glasses or without correction. A second pair of glasses could be tuned for things 0.5m-5m away
The problem with bifocals and progressive lenses is that they assume you are looking down to see close objects. For those that do close-up work, from SMD soldering repair to dentistry as well as individuals working in front of monitors, they are not a good solution, as the work is directly in front of the eyes.
One practical solution for computer work is 40" 1080p monitors at a farther distance. This takes research when subsituting a television, because many HDTVs that one might try to use at 1920x1080 do not have clear 1 to 1 pixels as advertised, even with digital input.
The coke-bottle tickness for glasses can now be much reduced by using high-densidy (and now even ultra-high-density) glass/plastics which have a (much) higher than normal refraction index, The higher refraction index means that you don't need as sharp a curve (and, thus thickness) to achieve the needed focus correction.
A you get older, your ability to change focus for various distances reduces, and so multi-focal lenses start to become valuable. When you first get them, they suck, but as your focus ability declines, they can become more useful. Bifocals (and, similarly progressives) are meant to give you easy access to reading at short (book) distances. Progressive lenses have two advantages over regular bi/tri focals:
The problem with progressive is that (as pointed out), they have a smaller sharp-focus field, at any distance, and they take more getting used to. (once you get used to them, they are, actually, pretty useful for a lot of things)
One problem for computer users is that -- especially for desktop uses, we often are reading at mid distances -- neither far focus nor book distances. This is outside the historical "Best Practice" for the optometric profession. The first time my mom 'surprised' me with progressive lenses, we had a long talk about how my distances were not 'normal'.
What I would suggest doing is talking to your optometrist about the standard distances you encounter at work. (use a tape measure and actually MEASURE the distances), then come up with a bifocal pair for those> distances... having some hard numbers will also make it a bit easier for your optometrist to determine whether multi-focal lenses are even a good idea. This would probably also mean talking to a real optometrist, and not just an optician (essentially just an optical technician).
The probable best result (my guess) would be two pairs of glasses -- one set for work distances, and another set for 'normal' uses. If you go that path, you might want consider avoiding the 'pretty' stuff for the 'work' pair (i.e. don't bother with really high density glass, or anti-reflection coatings) It'll make the second pair that much cheaper.
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Thanks for the elaboration, so there's basically four different styles of glasses? Is there another 'professional' or 'official' name for normal glasses or they're basically just 'glasses' and we refer to everything else with those names? I expect there's probably a more professional name than 'coke bottle'.
"Coke Bottle" is a pejorative term referring to the lensing effect on the persons eyes in order to correct their vision. The most common reason, historically, for "Coke Bottle" lenses was cataract surgery to remove the lens of the eye, before we had the ability to replace the lens. Mostly they are provided to very small children these days, when cataracts occur earlier, and general replacement of the lens is contraindicated.
The generic professional term for all non-vanity based glasses is "corrective lenses".
There are various lenses for various conditions:
- "myopia" is near-sghtedness
- "presbyopia" is far-sightedness, and if age related, is usually corrected by over the counter "readers" or "reading glasses"
- "macular degeneration" can be age related, or caused by a number of other conditions, such as diabetes, and results in damage from the center of the retina outwards; special glasses can "work around" the problem by focussing all light as a ring around the retina outside the area of damage, and depend on the ability of the brain to reintegrate it into a normal field of view.
- "Keratoconus" is a cone shaped cornea that will prevent a full field of view, since light no longer focusses un the retina; unlike macular degeneration, there is no retina damage, and this is fully correctable with special lenses.
Generally, if you care about thee things, or just find them interesting, you can always stop by a not-very-busy Len Crafters or other similar store, and chat up their optometrist or opthamologist, or just read about them on the net.
I have one toric lens contact for mild astigmatism. If I'm laying on my side for a while to work on the car or take a nap, my vision will be strange for a minute or so when I straighten up. They might not be the best choice for someone into extreme sports, figure skating with lots of high speed twirling, aerobatic pilots, etc.
Will
- "presbyopia" is far-sightedness, and if age related, is usually corrected by over the counter "readers" or "reading glasses"
Not exactly. Far-sightedness is hyperopia. Presbyopia refers specifically to the loss of "focal accommodation" with age; if you have otherwise normal vision, this usually manifests itself as loss of the ability to focus on close objects.
I've been strongly myopic from childhood. Now, in my early 50s, presbyopia means that without glasses I can only focus on things about six to ten inches away from my eyes, instead of things from two to ten inches away. With glasses, I can still see normally to infinity, but I need bifocals to cover both far and near ranges -- unless I hold the target up close and peer under my glasses.
If you start out with hyperopia (far-sightedness), and presbyopia sets in, you may not be able to focus at any distance -- your nearest focus distance may be beyond infinity.