Q: I always wonder if my vari-lens glasses affect my ability to balance.
A: Dear Vari-lens Wearer:
This is a good question! The answer depends a lot on each individual and how strongly you rely on your eyes for balance and alignment. In general, for new students, keeping your glasses on so you can see what is going on with you and also with the demonstrations you might be using to learn new poses can be essential for your progress. But as many more seasoned practitioners have noted, it is often natural to begin to close your eyes at times as you practice and rely on a more internal sense of awareness and balance for many poses. The obvious exceptions are balancing and arm balancing poses, like Tree and Handstand, but I have found myself on occasion closing my eyes in Headstand and Shoulderstand quite successfully.
The good news is that the eyes are only one of several systems that work together to assist in good balance, and the others can pick up the slack when needed. So I'd probably try periods of practice at home without your glasses, when looking at demos is not an issue. Then try it a bit in class and notice how it goes.
A: I don't know what vari lenses are but I do know what progressives are, as I have been a wearer of them for three years. In progressive lenses, the glass is graduated between far, closer and closest distances. And if you try to look through a part of the lens that isn't made to do that task, your vision is blurred. And if you have a slight astigmatism, this can in turn cause you to overwork certain eye muscles, which leads to head aches/eye aches. I don't understand all the ways new lens are now made, but in my own practice I have found that if I take off my glasses then my balance is more impaired than if I leave them on. However, if I take away all my vision by closing my eyes, it makes me work more with my other balance centers (proprioception, pressure sensation) and it actually improves my balance!
Although we use our eyesight to help us balance, we can indeed improve our balance by removing this or other senses from the equation. And I personally find that if my vision is impaired, it is more stressful for my nervous system because I’m trying to correct something that can’t be corrected. As someone who is extremely myopic, if I can't see clearly, I can't hear as well and I can't mentally focus. But if I close my eyes, my nervous system can focus on strengthening the balance sensors that remain. My other senses are clearer. I hear better because I direct my attention more to my hearing. I feel more, and I direct my breath into improving my sensation and relaxing areas that I might tend to overwork if I am using my eyes.
Like Baxter, I recommend that you experiment with glasses on/off. When practicing with your eyes open, try finding a focal point (something to visually focus on that you can see clearly) and use that to assist in balancing.