Ultra Violet Color Glow after Cataract Surgery with Crystalens

Countless people who have also had their natural lens removed have written me saying they see similar to what I describe below.

I've been very happy so far with the Crystals implant for Cataract Surgery - after a lifetime of glasses, it's life-changing to be able see good!
I expected some color shifts since my natural cloudy/yellow lens was replaced and it's wonderful seeing a "brighter more vivid" world. But one unexpected/interesting aspect is I see a violet glow that others do not - perhaps I'm more sensitive to the shorter end of the visible light spectrum. While I don't have a "Sixth Sense" that allows me to say "I see dead people" (!), I suspect I'm actually seeing Ultraviolet light! ;-)

Simulation of how I see in the Ultraviolet - mouseover image to see overlays

I've read that people who are Aphakia (do not or no longer have a natural lens) may be able to perceive ultraviolet light. A mainstream media writeup here and another here plus a personal experience that sounds familiar to what I'm seeing. An Eye Surgeon recently wrote about blue-violet color changes after Crystalens implants (PDF) and his experience is that only 3% of patients have experienced (or mentioned!) this phenomena ... but some people may just have more sensitive photoreceptors, so the vast majority of the patients would not see this.

The natural lens becomes increasingly yellow with age (which basically provides a Blue-Blocker filter) as seen in the image below. So I enlisted a few kids in the neighborhood to "volunteer" for me, and (compared to adults), they seem to see a bit more color glow on the black light, but nothing close to the huge difference I see with a UV filter or polycarbonate glasses.

The human crystalline lens at various ages from Sidney Lerman's "Radiant Energy and the Eye"

Unlike many IOL's, the Crystalens transmits some UV light and I suspect this may have been intentional by design in order to provide the clearest possible vision, especially in low-light. One medical literature review says the use of blue-blocking IOLs is not detrimental in visual acuity, color perception, and contrast sensitivity but another says blue-blocking IOLs decrease photoreception without providing significant photoprotection ... so even the experts don't agree. My eye-doctor-wanna-be opinion is Dr. Mainster is probably right - do not blue-block.
Several months after I wrote the above, out came this NY Times piece (related papers here and here) about aging eyes causing health woes.

Spectral transmittance of IOL's and crystalline lenses with median ages of 15, 25, 45, and 65 years
Click on image to see Dr. Mainster's chart in full-res

Here's Wikipedia's writeup on Color Vision that talks about the role of the Short, Medium, and Long cones in color perception. So perhaps a small percentage of people (myself included) have increased sensitivity in the S cones to light around 400nm (or shorter) ... but normally, the natural lens would filter that out - mine is now gone. It's worth noting that the "violet glow" is similar with both eyes. On a related note, I tested my color perception with an online FM100 Hue test and scored an 8 (seems pretty good) with the few errors in the green-blue area. I re-took the test (only takes a few minutes) in early/2018 and got none wrong - perfect score!

I actually noticed this the day after my first Cataract Surgery with my son's Colorado Rockies shorts (see below) and it adds a faint blue/violet sheen to the outdoors - indoors, most UV light is filtered. It does make sunrise/sunsets look even more awesome!

Here's a picture taken in the shade on a sunny day of my son's Colorado Rockies shorts and other misc.
The camera (and other people) don't see the purple glow - simulated with +20% Red & Blue channel
If I put a UV filter (or a pair of polycarbonate glasses) in front of my eyes, the purple glow goes away

So being the over-analytical engineer (!), I've done various "tests" of my UV vision. It's a little harder now that both eyes have been done (which I'm very thankful for from a visual acuity perspective), since I can not compare/test myself with and without natural lens. I can see much better than others in a dark room lit only with a "black light" ... although ironically, other people can see fluorescence (stuff that glows in the dark) better than me because it stands out more - i.e. the rest of the room is dark for them!

Another test would be using a (scientific grade) prism (or diffraction grating) to split sunlight into different wavelengths and compare what I can see versus other people. Probably the best test would be getting access to Monochromator which generates selective wavelengths and quantify what I can see at the shorter end of the visual spectrum and into the Ultraviolet.

My son has a very small prism that casts rainbow colors which are well highlighted on the kitchen wall.
I put a yellow sticky where I saw the violet color end, and then asked my wife and kids (age 13 & 10) to show me the "end of the rainbow" ... which was less than I saw ... and about the same as the camera sees.
Mouseover image to see wide-angle view of setup

I do see this violet glow in other situations, although not as visible (pun intended) as the Colorado Rockies shorts. Two examples are there is a ever-so-slight blue tinge on asphalt (but not everything per Cyanopsia) there is a slight "white haze" on greenery - both of these seem somewhat similar to pictures I've seen taken with UV capable cameras. Both of these go away when I put a UV filter in front of my eye. And before I had the natural lens removed from my second eye, I could perceive this difference with the already operated-on eye.

A number of people (most who are aphakic - i.e. no natural lens) who have read my writeup and visual examples of seeing ultraviolet light have written to say they have similar ability. Some related interesting tidbits include during WWII, the British used aphakics for signaling using UV lights ... since only they could see it. When the initial telescopic observations of Venus were done, a small number of people said they could "see more" ... which was later confirmed when UV sensitive equipment became available. Walter Scott Houston, a fairly noted amateur astronomer, wrote columns for Sky & Telescope magazine for several decades ... and after his cataract surgery, he was able to see "more" of the night sky with is new Ultraviolet vision. Another example is Claude Monet's painting being influenced by his cataract and subsequent UV vision after removal - PDF.

November 8th, 2011 Update: Andy Goris at Hewlett-Packard thought my UV vision was worth testing and graciously provided access to a Monochromator in his Lab. This uses an extremely bright light (which requires special cooling) and a diffraction grating to produce a very narrow (10nm) wavelength of light that is projected on a sphere with an exit port for viewing - i.e. this is some pretty serious test equipment!!!

The Oriel Instruments MS 257 Monochromator emitting at 450nm - note massive cooling radiator for source light

The test setup was in a dark room although there was some spillage of light from the monochromator bulb. I used a piece of cardboard to shield my eyes from this ... although a better approach would have been a black cloth completely draping myself and the viewing port ... which also would have prevented reflected light bouncing off the sphere. Andy's co-worker Murray then stepped through various wavelengths and I would describe what I could see in terms of color saturation, brightness, any difference when viewing through a UV filter & polycarbonate lens. The later was quite useful at the shorter wavelengths (which it filtered) as I could tell the difference between a "zero baseline" and what I could see.

Alek in front of the Monochromator - room was darkened for testing - mouseover image to see Andy demo'ing

Andy Goris after testing Alek's UV sensitivity with the Monochromator

Results/Conclusions: Andy had done some testing a week or so earlier with some co-workers and the vision cut-out for the 40-50 year olds was around 410-430nm. As shown in the test results, I was able to see quite a bit below that and still saw a bit of purple at 350nm and a tiny bit of brightness down to 340nm. So this seems to conclusively prove that I'm able to see into the Ultraviolet spectrum.

December 19th, 2011 Update: I picked up 400nm and 365nm UV flashlights to "test" my vision more. While both have some leakage into the visual spectrum (above ~400nm), the 365nm light is a faint/pale grey to "normal" people ... whereas I see a bright purple. So it makes for a very easy demonstration of my ability to see UV. Ironically, the 365nm UV flashlight did not have a warning sticker on it, although it would be more dangerous ... so I made a UV warning label. Here's a picture on a white pillow - remember that the camera doesn't "see" UV.

Use the controls to play, step, pause, slow-down, and/or speed-up the animation.

Jun 3rd, 2012: I get a variety of Emails from people about this webpage and JohnH wrote a particularly interesting one:
Back in the 1960's when I was a biology grad student at UCSD, there were reports that a spectroscopist named, IIRC, Gregorio Weber could see UV after cataract surgery too. At the time there was speculation that what he was seeing was not UV directly, but rather the UV-induced fluorescence of pyridine nucleotides and other fluorescent cellular constituents. The result was the same, of course, he could now perceive UV light with his eyes. I suppose the idea could be tested by looking at the action spectrum or by determining is the spatial resolution for UV was the same as for blue light.

That's a good question in terms of the actual mechanism of UV vision ... and I actually have not done any spatial resolution tests which would require an eye test on a chart only seeable in the UV spectrum ... seeing the purple'ish ting on a pair of "black" shorts doesn't count!

July 14th, 2013: I have been having a fascinating & informative Email discussion with Tom Clive, Dr. William Stark, and Dr. Klaus Schmitt.
While I can describe/Photoshop what something looks like in Ultraviolet, actually doing UV Photography is quite the challenge. I don't have the budget to replicate Dr. Schmitt's excellent setup, but it motivated me to fashion a "Rube-Goldberg" UV-Pass filter using Wood's Glass for my 50th birthday! ;-)

While this isn't a "perfect" UV-Pass filter, it does block a substantial portion of the visible spectrum. One easy and interesting test was viewing a Natural Gas Burner which looks blue to most people, but slightly more purplish to me. For a normal sighted person (my sons are always willing volunteers!), when they looked through the Wood's Glass, the flames become a "barely visible dark purplish" - remember there is still some leakage at 400nm. For me, the flames are still quite bright with a big change of hue from blue to purple.

Conversely, if a normal sighted person looks at the flames with the UV filter (not the "UV-pass"), they don't see any difference ... but for me, the purplish hue become blue'ish. Finally, when stacking the UV filter to the Wood's Glass, I see the flames become very dim dark purple - probably similar to what the normal sighted person sees with just the Wood's Glass.

2016/02 Update: I get all sorts of Emails from folks who also see UV, and in Feb/2016, HankR wrote me. He had an IOL put in one eye back in 1994 (apparently, UV blocking was much more commonly used after that). He still has his natural lens in the other and writes "Comparing 405nm for example is stunning -- faint violet with natural eye, brilliant purple with white center spot with operated eye (and yes it's scary). Turns out he is a pretty technical dude and bought a 5-pack of some ZWB2 "visible-light filters" (VLF) for UV flashlights (discussed in this forum post and excellent review here) and graciously sent me a couple to test.

I tried my "natural gas test" and compared to the Wood's Glass, the VLF is a slightly paler purple, but the flames are still quite visible to me ... versus hardly at all for a (willing!) teenage volunteer. A more noticeable difference for me was when super-imposing the UV filter. Instead of a very dim dark purple with Wood's Glass, I could barely see the flames with the VLF ... and in fact, had to get much closer to make out an extremely pale grey. The teenagers saw no difference with the UV filter ... as expected. I also tried with my 400 and 365nm flashlights - the VLF knocked down the lights from the 400nm quite a bit more - less of a difference on the 365nm flashlights. So my conclusion was that the VLF is a pretty effective filter and better than Wood's Glass at filtering visible but letting UV pass through. I actually did these tests before I analyzed the spectrum transmittance chart in the posts above ... so it was cool to see that those support my observations.

Dr. Schmitt used his UV sensitive camera and special UV transmissive lens to simulate Human UV vision. While I don't have his sophisticated gear to duplicate that, I can use my "Mark I Eyeball" and my Wood's Glass UV-Pass filter to see if my view is similar to his photography. Dr. Schmitt identified the flower below (from my backyard) as a Gazania and email'ed a Ultraviolet image. I "see" my flower similarly in UV when looking at it through the Wood's Glass during daytime, although it's hard to block out all the light plus there is some leakage.

Because this flower closes up at night, I had to clip one and bring it inside to a darkened room to use my UV flashlight to illuminate it - this was a better way of viewing it. One minor differences I see compared to Dr. Schmitt UV picture is that the dots in the center are glowing purple to me rather than yellow ... but he pointed out that Gazanias come in many variations and their UV patterns vary quite a bit. Also, on the "leaves", I see the white at the tips and the black in the middle ... but I actually see an dark-orangish color bordering the black where the purple is. However, if I use the Wood's Glass, that goes away. This leads me to believe that the flower may be fluorescenc'ing from the UV light into the visible.

While my poor-man's UV-pass filter using Wood's Glass has some shortcomings, I was pleased with the "more UV view" of the world it provided and it was nifty to be able to compare against UV images taken on the other side of the world! ;-)

August 14th, 2013: Roger Cicala writes a fascinating blog entry on the Lensrental Blog titled "Fun with Color Vision. While it doesn't talk about UV, it's a great read about how your eyes work and brains processes visual information.

In summary, my UV vision is an uncommon (my photoreceptors may be more sensitive) but not unexpected side effect from Cataract Surgery.
But HEY, I've got a "superpower" ... so maybe this middle-aged Suburban Dad should start wearing purple tights and a cape! ;-)

Captain Ultraviolet to the Rescue - click here if you need a crime-fighter wearing super-cool Blue Blockers!

Here's a few of the funnier Emails Captain UV has received about his new superpower:
BrianA: I am glad to hear things went well from your surgery. You have to think there is a sideline business opportunity in sunscreen rating with your new UV powers. :)     Alek replies: Yea, SI should hire me for sunscreen quality control when they shoot their swimsuit issue!

GregO: Oh, I get your secret evil plan! Steps to superman transformation: X-Ray vision. check. Steel green hands. check. Secret super cave disguised for Halloween. check. heh heh... you are my hero!

AmyH: Sure enjoyed hearing about your new superpower! Remember, with great power comes great responsibility -- Spidey's uncle.

Happened to noticed that the Skeptics Guide to the Universe did a podcast that talked about my UV vision - here's an excerpt just about that.

Contact me with any corrections/questions/suggestions.
And if this was helpful, there's a link on that page if you want to buy me a beer ... or some Big Mac's! ;-)