Health Effect of psychedelics on 3D stereo vision, maybe permanent

[trees-are-imposing]

Most people have two eyes, and can use them together for depth perception, forming a 3D image of the world around them. That's stereo vision, and it's very helpful in playing sports, driving a car, threading a needle, etc. About 7% of adults can't, though. Most of those people have okay vision in each eye alone; their brains just can't align and fuse the two images properly.

For a long time, scientists believed it was impossible for those people to ever see in 3D. Perhaps for that reason, most optometrists don't routinely test for this, and most patients are unaware that anything's wrong--one might know they're a nervous driver, but not the reason why. But about twenty years ago, a biology professor successfully recovered her own stereo vision. Since then, many other people have too, though there's still no reliable treatment. About a year ago, I did myself, in a surprising set of experiences involving LSD; see my post history on reddit (same username) for details.

I'm curious to know what role the drug might have played in my gain. I've found a few other anecdotes, but nothing beyond that. I therefore thought I'd post here.

Is there anyone else here who doesn't have stereo vision normally, but does have it on LSD or another drug? You can test your stereo vision in a few ways, including:

1. View a 3D display, like a Nintendo 3DS, or any VR headset, or a 3D movie on a normal display with red-blue glasses. You should perceive the depth. Close one eye, and the depth should go away; if it doesn't, then it wasn't stereo vision. (This test is the best one, if you have the equipment.)
2. Put a dot of colored tape on a plain white wall, and stand a few feet back. Hold one finger a couple inches from your nose, in line with the tape. Look at your finger, and you should see two tape dots. Look at the tape dot, and you should see two fingers. (This test proves that your two eyes are working together, but it doesn't prove you're seeing depth.)
3. View an autostereogram, like a "magic eye" poster. (This test proves that you're seeing depth, and doesn't require special equipment. Even people with otherwise normal stereo vision may have trouble seeing autostereograms, though.)

If you don't have stereo vision normally, then I'd be interested to know your experience the next time you use LSD or any similar drug. If you do manage to get stereo vision--even temporarily--then it's really magical; I especially like the way trees and other plants look, or I've heard falling snow is amazing. The first few times I experienced stereo vision, I though it was just a hallucination; but I eventually understood it was real, and have so far managed to keep it full-time.

Take care that medical attempts to recover stereo vision (usually without drugs, using special eye exercises) have in rare cases caused permanent double vision, if the patient succeeded in using both eyes but failed to fuse the images together. Patients known to have amblyopia (lazy eye) or strabismus (eye turn, squint) are probably at higher risk. If you do experience double vision on LSD, then it will almost certainly wear off with the drug; I've seen many reports of temporary double vision there, but none of permanent. I'd still try to minimize any experience of double vision, to avoid reinforcing that unwanted perception through use. For example, you could try to find something else to look at that doesn't cause the double vision, or just close your eyes.

Thanks, stay safe, and good luck. I'm especially interested here in the potential for a legitimate medical use of psychedelics, with a more objective endpoint than the softer psychological conditions for which these drugs have also been proposed. A group at UC Irvine reports efficacy for ketamine against amblyopia deliberately induced in mice, and proposes a biochemical mechanism; so while this is definitely speculative, I don't think it's completely outlandish.

 

[iridescentblack]

I had to kind of scratch my head at this after I saw it the other day.

I remember talking about this subject with friends; when we were high we would sometimes talk about stereo vision. Back then we didn't have a name for it. Stereo vision with weed seemed only temporary and I don't remember when I first noticed that I had it permanently, but my stereo vision was rather short lived to call it permanently, (like maybe 1-2 years) and unfortunately it left me for nearly a decade when I was on antipsychotics. It didn't come back until recently when I was staring at a black Mazda going uphill. It was like an anchor attached to my ability to focus suddenly was cut loose and the stereo vision was back.

 

[fastandbulbous]

I have permanent trip vision in the dark, due to long term use of psychedelics, but don't think my depth perception is skewed

 

[trees-are-imposing]

Stereo vision with weed seemed only temporary and I don't remember when I first noticed that I had it permanently, but my stereo vision was rather short lived to call it permanently, (like maybe 1-2 years) and unfortunately it left me for nearly a decade when I was on antipsychotics. It didn't come back until recently when I was staring at a black Mazda going uphill. It was like an anchor attached to my ability to focus suddenly was cut loose and the stereo vision was back.

Very interesting, thanks and sorry for the delayed response. Do you have any other symptoms of amblyopia (lazy eye), like blurrier vision in one eye, or distortions other than blurriness, like a black spot or other obstruction that blocks your vision when you close your stronger eye? And do you think you have the stereopsis back full time now? I still have it myself, and still find it remarkable.