Question Short-term change in vision- possible causes?

[M.ronda]

I've been freediving for a year+ now (certified) and had a strange experience recently - my instructor & doctor both had never heard of it. I typically dive to 10/12m and hang/swim at that depth, although I have previously gone to 19m.

I was line diving to 20m 3x (with long surface intervals) and equalizing my ears/mask (I think fully). Ten minutes later, while swimming at the surface my vision changed - there was a red/pink tint to everything (e.g the clouds were reddish etc.) I took off my mask and within a minute returned to normal colors. I took a break but a week later the same vision change happened after repetitive dives to just 7m, and I felt faint/woozy for hours after. No change after just wearing my mask at the surface with no depth.

Any ideas what this could be? Many thanks in advance!

 

[M.ronda]

Ps. My eyes were white and not at all blood shot after each dive.

 

[erixsparhawk]

Ps. My eyes were white and not at all blood shot after each dive.

Very interesting, off the top of my head I can think of a few possibilities:
1. seizure - can present with any focal neurological sign, like the vision change you mentioned. Would tend to reoccur exactly the same with the same provocation.
2. optic migraine w/ transient tritanopia - basically a blue/yellow color blindness that causes everything to look red.
3. some medications like in TB and anti-psychotic treatments can cause strange visual changes.

 

[SBOffshore]

I had a similar experience one time. I was diving in a quarry down to 30 meters. When I was almost at the bottom i had a very rapid change in vision. I later figured out what happened. As I was clearing my ears, I was pinching my nose so tight that I wasn't allowing any air into my mask. I dive with an Aqua Sphere mask which is low volume with plastic lenses, so it gives under pressure. As I dove deeper and deeper the air inside the mask compressed (mask squeeze). At about 30 meters I felt a slight "pop" in my head and my visioin blurred. Freaked me out, but I was fine. Took me a while to figure it out. I did get a a little bloodshot in one eye, but no lasting change. I think the "pop" was actaully air escaping my nose and equalizing the mask.

So, check it out next time you dive and be sure to blow a little air through your nose into your mask to equalize the pressure there as well. Especially if you have a mask with a glass lens.