I'm not an eye care professional. I researched the issue of blue-light blocking IOLs several years ago before I had yellow-tinted Acrysof lenses implanted in my own eyes. l'll summarize my findings for you.
The yellow-tinted Acrysof IOLs are manufactored by Alcon. All of the studies that found no problems associated with these lenses were funded and carried out by representatives of Alcon. On the other hand, all the studies that did find problems associated with the yellow-tinted lenses were funded and carried out by representatives of AMO, Alcon's major corporate rival. (I conducted research when I was a grad student, and I know that you can manipulate the design of a study so that it's much more likely that you'll get the results that you're looking for.) I could find no credible evidence that the blue light-blocking feature helped to prevent age-related macular degeneration.
The cataract surgeons I consulted here in Chicago only used Alcon IOLs. Apparently, it was just too expensive for the surgery centers to stock more than one brand of IOLs. I went ahead and got the blue-light blocking lenses, and I have been extremely happy with them. I have never had a problem related to color perception (although I've read one or two reports about other people who claimed that they did have problems.) There may be another issue involved here. Strangely, the intensity of the yellow tint is related to the power of the IOL on a continuum. IOLs used to correct very farsighted eyes have the most intensely yellow tint; those used to correct very nearsighted eyes have the least tint. (I was very nearsighted before cataract surgery.)
So you will have to weigh your priorities before making a decision. You are very farsighted, so you would need IOLs with the most intense yellow tint. On the other hand, a toric IOL is the most reliable way to correct significant astigmatism (and I believe that the Acrysof toric IOL is currently the best toric IOL available.) Of course, you could also get an IOL by another manufacturer (maybe a monofocal Tecnis lens made by AMO) and have limbal relaxing incisions to reduce your astigmatism. Or you could get Tecnis monofocal IOLs and wear glasses with an astigmatism correction.
If you could see your own cataract you would see that the lens instead of being crystal clear as it was when you were a child is yellow-brown-white. It selectively blocks out the blue spectrum so it has probably been years and years since you have had true color perection.
When people have cataract surgery the first they they remark on almost universially is the wonderful color vision. Some very observant people think things are "too blue"" because for sometimes decades the blue has been washed out of everything they see by the cataract.
You are obviously scientific directed and know how to search the literature. You can use PUBMED or a internet search engine to read some papers about how blue and yellow tinted lens affect color vision. Generally they cause no problem and help protect the retina from UV light and macular degeneration. Your situation is unique and no studies are available on it. I suggest you discuss it with your surgeon.
In any case if you have a clinical cataract the vision you now have it likely much worse and the color perception much worse than it will be after surgery.
I am a textile craftsperson, and the ability to distinguish subtle color differences is obviously most important to me. When I developed galloping cataracts several years ago, I was very concerned about the slight yellow tint of my proposed reStor lenses. Like you, I could not get much information about what effect that tint would have on my color perception. Ultimately, my doctor reassured me, saying I would probably not be able to detect the tinting at all.
During surgery, as the still-folded lens was being inserted, it was a bit worrisome to see its quite yellow character, but when it unfolded, I really could not see any color at all.
Very shortly thereafter, I returned to embroidering and found that if anything, my ability to discern colors--even colors in low light situations (which may be relevant to your question)--was, if anything, heightened.
BTW, my lens implants have in fact given me wonderful eyesight. What an invention!
With the Olympics going on it London it is perhaps a good time to say that intraocular implants were invented in England by Sir Peter Choyce MD who made them out of the same plastic as the canopies of the British Spitfire fighter planes. He noted when fragments went into the eyes of pilots the material was very well tolerated and induced no inflammation.
He inserted the first IOL to much criticism from his peers in the late 40's. He lived to see his invention become one of the most important developments in ophthalmology-sight-vision in the history of the world.
Thanks very much for the reassuring words.
I am actually very excited at the prospect of seeing better. +8 flip down reading glasses aren't really much fun - especially around dust.
I was just worried that they might be tinted to a sort of sunglasses like level. As you can imagine - trying to see faint galaxies at the edge of vision with sunglasses on at the eyepiece would be slightly futile. Looking at bright planets with a neutral density filter isn't so out of the ordinary - but bright objects are not exactly my primary area of interest in astronomy.
I take it that the tint merely mimicking the natural eye's own level of optical transparency?
I don't have cataracts - so this will be a clear lens exchange operation - not that is particularly relevant since it boils down to much the same procedure by all accounts.
Thanks also for helping other people out like this - I notice you help a lot of people Dr Hagan. It shows a lot of compassion for people. Thanks also Achillea I'm glad it worked out so well for you!
FIRST LET ME CORRECT a mistake. The father of the IOL is Sir Harold Ridley MD not Dr. Choyce. The latter designed a very successful anterior chamber IOL.
The tints are to protect the retina/macula from ultraviolet and infrared light which can cause macular degeneration and which the human lens does.
I have never read an article that states that blue or yellow lens alters color perception but I would encourage you to do your own research and discuss with your surgeon.
I wasn't worried about colour perception per se. I was worried about how tinting affects the eyes low light contrast sensitivity in what I believe is termed scotopic conditions. Astronmers use averted vision which mostly activates the rods (don't cite me on that - I'm no expert).
I've done some research and it does suggest possible reduced contrast in low light - in the blue end of the spectrum - so I'm now in a quandary about whether to pull out of the surgery unless the surgeon can find me an equivalent lens that isn't blue blocking.
I've got a huge investment in visual astronomy equipment. Some of my lenses cost $1k alone and I spent a year building a 16" newtonian reflector - so I'd be gutted to find out that I lost sensitivity on the faint extended astronomical objects rendering my equipment useless.
I bet the studies with regards to patient satisfaction don't have many astronomers working in scotopic conditions - it's not simply walking around at night on a lit street.
I thought it might help to show some citations rather than just merely saying 'I found some references on the subject'
And another reference to the issues I'm referring to. I hope the surgeons don't have a learning curve with other products or are resistant to obtaining different lenses due to vendor relationships or suchlike.
I know it probably isn't an issue for most people but it annoys me that Alcon effectively cripple their prosthetics. It's really sad and depressing you can't get them without the tint ie at least get a choice in the matter.
From what I've read I would agree with your analysis that in other respects they are the best on the market. I just wish you could order them with this accursed tint - it seems to be a solution in search of a problem - given the lack of hard evidence on the benefits.
Don't laugh--but when I first read the research that constituted the "scientific" basis for Alcon's blue light blocking, I wondered whether the idea originated in their marketing department. What a sales pitch--an IOL that prevented age-related macular degeneration! And no one could prove that the yellow tint didn't work--at least not for many years.
Strangely, I believe that an older version of Alcon's ReStor was available in 2 versions: both with and without blue light filtration. I seem to recall reading that the version without the tint was marketed to people in certain professions who needed exceptional color discrimination ability! (If you do some extensive online research, you can probably find the reference. Or you could try calling Alcon's customer service.)
My Acrysof lenses are aspheric (without astigmatism correction), and there's only one feature that I don't like. In certain lighting conditions, my IOLs have a visible glow to onlookers. (It's similar to the glow in the eyes of the alien children in the old horror film "Village of the Damned".) I believe that all the yellow tinted Acrysof lenses share this feature. Lenses from other manufacturers (such as the one-piece Tecnis monofocal) don't emit a glow.
I don't know what your goals are for your post-surgery vision. For a refractive lens exchange, you could probably find a surgeon willing to provide a no cost LASIK touch-up to eliminate astigmatism and any residual refractive error. This option would eliminate the need for a toric IOL, and it would probably provide your best uncorrected vision. Alternatively, limbal relaxing incisions at the time of surgery might also work well, depending on the skill of the surgeon.
I wondered what they meant by eye glint - it's kind of cool that now that I'll be eligible to star in the next exorcist film :-)
I rang surgeon after I wrote my first post to identify the exact lens they are going to use rather than just guessing. It's a Acrysof IT Toric Lens. I'm happy with all the features of the lens itself with one noteable exception of course :-)
I'm also happy they seem to think it has good rotational stability - as long as they get the positioning right in the first place.
It's a good hint re: the Lasik touch up - I must remember that just in case and hope they won't have to of course.
I found this brochure that shows their range of lenses and some of them were clear - just not this particular type. I think I'm going to have to suck it up and take it - I don't think I like the alternatives very much - it's just such a shame about the tint.
Deep sky astronomy is all about hunting faint galaxies on the edge of perception. It's quite competitive in terms of whether you can see what your fellow observers are looking at. It's a crying shame I'm going to lose the edge that I could have otherwise had and inherit the yellowed eyes of an elderly person at such a young and spritely age ie. 43 lol :-)
Just an edit on the lens type - I made a typo
It's an Acrysof IQ Toric Lens. I'm a fumble fingers these days on the keyboard...
Good luck with your surgery. I really don't think that you'll lose the edge, and you'll be able to use your old glasses as a paperweight.
Jodie, about 2 1/2 years ago when I got my reStors, I ran into references to an earlier, untinted version--which was of course what I would also have preferred, but which was not available for my surgery. As it happens, my color vision is superb (she said in all modesty), though I obviously have not tested my dark adaptation for astronomical tasks.
It seems that the addition of the yellow tint was based on genuine concern about damage caused by exposure to certain wave lengths, as discussed (and referenced) in this paper:
MrAstro, you will also find technical mention here of dark-adapted scotopic spectral sensitivities. You may find it reassuring.
As an aside, my husband has also noted the 'demon glint' from my implants. He says it's a tad eerie, all right.
I have Acrysof Toric IOLs with the blue tint...no color problems at all..in fact, my color perception is better then it has ever been, certainly better then when i was nearsighted and wore glasses (prior to developing cataracts)...
Oh just to clarify, i didn't mean tint i meant the ultraviolet light filtering..whatever that is...LOL
I downloaded and read the paper you referenced. The author is a paid consultant for Alcon (the manufacturer of Acrysof IOLs), as stated clearly in the paper. (How could I have known this before even downloading the paper?) I've been told that the fees paid to a consultant involve six figures in terms of US dollars. This makes me more than a little sceptical about any "genuine concern about damage caused by exposure to certain wave lengths" on the part of the author.
I was not able to find any credible evidence that Alcon's blue-light blocking feature helps to prevent age-related macular degeneration. As I recall, the basis for this claim was some weak correlational findings that did not hold up to re-evaluation. On the other hand, I could find no credible evidence that this feature was in any way harmful.
Here is a more recent evaluation of tinted vs untinted lenses, published under the same aegis you find suspect:
It is of course possible that the information contained in these papers may be tainted by commercial interests, but for those with some background in physics, such as MrAstro, the plausibility of the arguments be significant.
I noticed that too Jodie and I'm very sceptical that a filter would increase scotopic vision.
How many eyepiece manufacturers for astronomical telescopes sell them with integral filters. (rhetorical question)....
Any filter is going to decrease the available light reaching the eye - even if it is in a narrow spectral range.
Notice that they say it increased under different assumptions - I'd like to know what those assumptions were - maybe it was a light source which didn't include the filtered wavelengths :-)
The ridiculous thing is age related macular degeneration would occur in people with a yellowed natural lens anyway - so much for blue filtering (via natural biological processes) preventing age related macular degeneration.
I sort of want to take some action regarding my lack of choice - but like I think I mentioned earlier I feel a bit powerless in the matter. My pre screening examinations cost $600 - it's hard to back out and find someone else - and then the other manufacturers lenses aren't without problems either (notwithstanding that they might be clear).
The frustrating thing is I bet it would be easier for them to manufacture a clear lens than a yellow one.
Hi Mr Astro,
A few points for your consideration;
* The yellow tint (violet or blue blocking) is designed to filter out potentially harmful rays, but it does alter colour perception, as is evidenced by many patients who have an untinted lens implanted in one eye and a yellow lens in the other. They often can notice the difference. Whether this would affect your work, I don't know?
*You mention you are hyperopic with some astigmatism. To my understanding, the Alcon lenses are available in 0.50Dincrements for common dioptric powers for the spherical component of the lens and for the cylindrical component that corrects for the astigmatism they come in 0.75Dsteps. This means that you will get a lens that is the closest fit. There are more recent advances in manufacturing that have allowed some European manufacturers to offer custom made toric IOLs that are manufactured to your exact requirement in 0.01D increments for both the spherical and cylindrical component. This may in fact have a greater impact on your ability to see well post surgery? These lenses are not available in the US? Not sure where you are based? Oculentis in Germany offer the lenses manufactured to 0.01D and Lenstec offer them to 0.25D. I am not sure if you can get the later in the US. Oculentis offer a yellow lens, not sure about Lenstec.
Good luck with whatever you choose and it will be nice for you to hopefully not need your +8 glasses all day long anymore!
And again...i have the Acrysof torics with the uv ray filtering...to be honest, i don't notice any difference in the way i see colors then i did prior to getting my cataracts and wearing glasses...in fact, the filtering seems quite beneficial in that i find i never seem to need to wear sunglasses in any situation outdoors...
To use an old expression...i think you might be making a "mountain out of a mole hill"...i am sure you will be so happy with the way you will see after the surgery that you won't even notice any difference either...