An interesting way to figure out eye problems

I was diving in Coz in April. I bought the iTorch Video Pro6 for video and was impressed with the light output and quality of the light. When not using it for video, I used it as a backup light on night dives. It turned out that it's actually too bright and diffuse for night dives. I needed a more piercing beam.

We did a night dive towards the end of the trip and stopped at a small cove just before the exit point at SCC. I switched to the iTorch - the power of the light was astounding. The diffuse nature of the beam LIT up the cove. We saw absolutely everything in there. I decided to use the "UV" option to see if there was any luminescence inside. When I turned it on, I could only see out of my right eye. Left eye was effectively blind. I changed back to white light and left eye turned back on. Back to the UV and same thing again. It was quite scary.

I finished the dive and went back to my room and did the same thing there. Once again, the left eye became inoperative. I knew that the UV option is effectively a purple light at 420nm and should not cause any blindness. At no time did I ever shine the light directly into my eye. I went to the ophthalmologist when I returned who immediately diagnosed me with a rapidly deteriorating cataract. Within three weeks after diagnosis, I was legally blind in that eye! I had the cataract successfully removed yesterday.

I must say that I'm puzzled by the UV blinding effect. Any optical physicists out there that can shed any light (sorry) on this? It did not happen with the red light nor the lower power white lights. (And oh yes, there was no luminescence in the cove).

tridacna,

That is a pretty cool story. I enjoyed reading it Glad we helped you figure out you were blind to UV in the left eye!

Thanks for supporting us!

I recently read that the human eye has some UV receptors, not as many as bees have for example. Perhaps you have more UV receptors than many, and those were the receptors first affected by the cataract, and the RGB receptors and B and W receptors were affected later.

Very interesting. Wonder if your cataract surgeon has written up a paper on you.

Love that light! 20/15 in both eyes since surgery. And both of my buddies bought the iTorch.

---------- Post added August 20th, 2014 at 09:01 PM ----------

shoredivr:

I recently read that the human eye has some UV receptors, not as many as bees have for example. Perhaps you have more UV receptors than many, and those were the receptors first affected by the cataract, and the RGB receptors and B and W receptors were affected later.

Very interesting. Wonder if your cataract surgeon has written up a paper on you.

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Interestingly enough, my eye surgeon seemed nonplussed by my story. As soon as I told him, he "knew" that I had a cataract there. Examination immediately confirmed his hypothesis. I know that humans cannot perceive light in the 300-400nm range but it's strange that that specific wavelength blinded me. Perhaps I need an optical physicist to try and explain... ?

Human retina has UV-sensitive photoreceptors

a bit about UV perception, and some personal speculation.

Interesting. Quite controversial. Tetrachromacy doesn't explain my issue. Why would a UV light obscure my vision? Remember that the right eye was OK. (I had a cataract removed from that one previously). There is obviously a great deal of other spectrum light in the "UV" mode otherwise, we would see nothing at all. Quite puzzling.

Post this in diving medicine and see what responses you get, or maybe ask DAN. I agree it's interesting.
I like puzzles.

Could the UV light have been flourescing on the cataract and you were blinded by the light, so to speak?

BRT:

Could the UV light have been fluorescing on the cataract and you were blinded by the light, so to speak?

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That is an interesting theory. Perhaps reflecting off the cataract too?

Interesting. I'll have to try that to see if my right eye goes blind in UV. I've suspecting a possible cataract in it. Of course I could go see my optometrist!