A link between clinical depression and strabismus is a topic which repeatedly comes up in conversations among people in our DIY Vision Therapy group. It does seem that there are higher than average levels of clinical depression in those with strabismus based on my ignorant and wild guessing.
My understanding of what depression is, for a lot of people, is the result of the mind running amuck. Everyone has an internal dialog, but for depressed people, their internal dialog is particularly repetitive, active, and impulsive. The parts of our brain which do thinking are connected to the parts of our brain which do emoting, so every time we have a thought we have an associated emotion. So if you have constant, repetitive thoughts that are negative, the result can be chronic negative emotions which can become clinical depression (as opposed to transient depression).
This link between the thinking and emoting parts of the brain is what cognitive behavioral therapy is based on. The purpose of CBT is to break the constant cycle of negative thinking and the related negative emotions, and thus, stop depression. This is also what many PTSD treatments are based on. People who have PTSD symptoms suffer not simply because they suffered a traumatic event. They suffer because they're repeatedly experiencing the same traumatic event again and again in their minds. When you revisit old traumatic memories, the brain and body don't realize that what they're experiencing isn't real. So you really are reliving the experiences again and again, and your body is paying the toll of constantly activating the sympathetic nervous system and the cascading stress effects.
This cycle causes brain damage, substance addiction as a result of people trying to manage the pain, and mental collapse. It's no doubt largely responsible for familiar picture that Americans have of homeless vets. There are new treatments which use LSD and MDMA, which are supposedly very effective for PTSD. The purpose is to allow the patients to experience the traumatic memories without the associated negative emotions, and thus, stop the pain and constant grating on the body's fight or flight systems.
A little while ago I was listening to a fascinating conversation between Sam Harris and Joe Rogan on Joe's podcast about the topic of mindfulness. Sam was talking about the irony about how most people have an internal dialog, which, if it was uttered aloud, they would appear to be completely insane to any observer. The only difference between a 'normal' person and an overtly mentally ill homeless man talking to himself is he's making his internal dialog available to everyone around him. Most of our internal dialog is a repetitive, futile waste of brain cycles--and not to mention, harmful to the end user. Sam asked the question 'Why is it that we consider this normal?' Indeed.
This is sort of interesting to me, because it's only recently that I've started to get serious about meditation (the past four months). I'd read about all of the benefits from recent brain studies, like increased brain mass, improved learning, and focus. Since I was hearing so much about it from legitimate sources, I thought I'd give it a try. I'd done it a bit in the past, but stopped for whatever reasons, so I already had some idea of what I was doing. In revisited experience, 10-15 minutes of meditation--even somewhat crappy meditation--since I'm still bad at it, is extremely beneficial to my mood, and focus during the day.
The main things that I've noticed is that I'm much calmer, and seem to have an almost unlimited focus. My drifting is very not much. It's resulted in me doing a lot of cleaning and organizing. One of the interesting things I've noticed since I've started doing meditation again is that every once in a while I'll get a nice high, whether while doing meditation, or while doing nothing, or waiting. Yesterday I was at the gym doing squats, waiting between sets, not doing anything. I was relatively mentally silent. All of a sudden, everything seemed to go quiet. I was suddenly aware of my body, the music playing in the gym, and all of the other bodies moving around, doing reps and moving their legs in circular motions. It felt like a real high, and a lot of happiness of being right there, right then.
My morning routine is 15 minutes of meditation before I go out of the door. One of the things I've noticed is that I can know very accurately how well my day is going to go depending on how well I do with meditation. I occasionally meditate very crappily and my day will consequently suck. Other days I know that I did very well, and the day will be excellent as a result--regardless of what happens. It seems to be a very good predictor. If meditation goes well, I can't have a bad day. I still do drift, and I still do have some insane inner dialogs, but I'm aware of it and I think to myself 'Oh, Andy, you know better than that.' I suppose that's the whole point of mindfulness.
You might be wondering what this has to do with strabismus. Here's where I'm going with this. If there is a link between strabismus and clinical depression, maybe it's because visual processing takes up a lot of brain power. After all, the visual cortex is a giant part of the brain. People who are using only half of the available visual input via suppression thus have more brain cycles which can be used for other things--like dysfunctional thought. For people who have normal stereoscopic vision, there are fewer spare brain cycles available for repetitive thought, and thus neurodysfunction.
It does seem to me that people who have normal vision are more 'there'. They're more engaged and part of what is going on around them. Therefore, they're going to have less going on internally, and fewer repetitive, dysfunctional thoughts.
When I'm having a conversation with someone, it's not uncommon for me to look at him in the eyes and wonder about what he is seeing, and what his experience of consciousness is like. People on, average, do seem to be very much 'there' and in the moment. Like, when people watch sports, their eyes are very intensely trained on what they're seeing, and it seems like the whole system is working in synergy to recreate what they're seeing and participate in the event.
One thing that comes to mind is something Heather said. She's someone who had strabismus, but recovered full stereoscopic vision through vision therapy. She said 'I feel that the world is more real.' It sort of goes hand in hand with something Susan Barry said, something like 'I feel like I am now in the world.'--like more of a participant. They say that seeing in stereo is a fundamentally different experience.
People like Heather are important to me because she's one of the very few people who understand what it's like to live in both worlds. There is a Reddit AMA that linked to in previous entries that I'll repost here. It's some guy who recovered stereopsis via surgery. He said
He's completely stunned by the visual phenomena, and just seeing people walk around in a crowded room, still adjusting to all of the visual information. Maybe it would be harder to be taken away by dysfunctional thoughts when you're so occupied by what's so violently grabbing your visual attention.