Yoga Musings: Drishti, Myopia, and Presbyopia

Drishti is where you direct your gaze during yoga poses.  It's underemphasized in yoga teaching.  There are some standard places where you can settle your eyes.  In many forward facing poses, eg. Warrior I & II, you gaze out at the horizon.  In other poses, you gaze out at your hand or fingers.  Still others, you gaze, or at least try to gaze, at your own nose or you roll your eyes up and try to gaze at your third eye (spot between the brows).

Myopia, or earsightedness develops in children, teens, and sometimes adults.  While growing up, I always thought my nearsightedness was genetic.  It isn't.  It's a direct result of muscular action.  Most myopia is, actually.  My advisor always likes to give the anecdote about the airforce here.  When the airforce started recruiting pilots, they had to find extremely intelligent men with perfect eyesight.  Well, most intelligent students go through our school system and end up with myopia.  Why?  Studying and reading books.  The airforce ended up identifying students who were so smart that they never studies.  These were its ideal recruits.  The problem is, once they were recruited, they then had to study to become pilots.  Yep.  This involved a lot of reading.   After pilot training all these genius students had lost their perfect vision.  Finally, someone came up with a solution and gave all these pilots reading glasses.

When we read, our muscles contract around the eye to change our focal plane to the distance of the book.  When this happens for long hours at a time, say reading, writing, or working on the computer, the eyeball slowly gets pulled out of shape.  Our natural, resting focal plane slowly becomes closer.  It was on the horizon.  When we are +1.00 diopters myopic, it's at 1m, +2.00 diopters gives us 0.5m, +3.00 diopters gives us 0.25m, and so forth.  Reading glasses readjust the focal plane so that our resting focal plane is @ 1m or 0.5m, allowing us to focus on something at that distance without having to use our muscles to adjust our focal plane.  Thus, long hours spent don't involve long hours of muscles pulling on the eyeball, slowly bending the eyeball out of shape.  Contemporary optometry, unfortunately, does the exact opposite. When a child becomes myopic, they can no longer focus well on the horizon, so we give them negative diopter lenses so that their focal plane moves back to the horizon.  Then the child sits down and studies, and parents and teachers tell them to wear their glasses.  Well, the glasses make them focus at the horizon, so their muscles have to pull again to make the focal distance closer.  The child gets more near-sighted, the doctor then gives him or her stronger glasses, and the next time the child reads, the muscles have to pull again.  The dance continues and we get people like myself with -8.50 diopters of myopia.

Why am I bringing all this up?  I think daily yoga practice with a strong emphasis on drishti can halt or slow presbyopia and reverse near-sightedness.  Halting myopia is easy.  Hell, just giving a kid reading glasses will halt the development of myopia.  Reversing it is another matter.  There are a few infomercial kits who say they can reverse it.  I purchased one once, it involved a lot of exercises requiring constant switching of close and far focal points.  I believe the idea is that this develops the muscles in the eye which control focusing.  They also had some practices like putting a warm towel on your eyes.  I'm not sure what end that serves, but it perhaps relaxes muscles and possibly the eyeball, allowing the eyeball to revert to its original shape more easily.

An hour long yoga practice with strong emphasis on drishti would involve constant refocusing and movement of the eyes.  This serves the same purpose and should exercise the muscles enough so that presbyopia does not set in.  As for reversing myopia, the same principle that applied in making one myopic may apply.  I'd have to look at some eyeball anatomy to be sure, but there may be a set of muscles antagonistic to the primary flexing muscles which cause myopia.  These may enable one to stretch the eyeball in a manner as to reduce myopia.  To engage these you would have a natural focal distance of say 1m or 5m, and then attempt to focus on the horizon.  That is to say, if you used slightly less optimal contacts or glasses, you wouldn't see the horizon perfectly, and would have a natural focal distance closer than infinity.  By attempting to focus on infinity, you would be reversing the action that caused myopia, and perhaps cause your vision to improve.

PS> One of the more annoying things during a yoga class is to have a teacher who doesn't speak loudly enough.  A student is flowing through the poses, and the vocal prompt of the teacher invites the next movement.  This allows one to focus on the now, the breath, the movement.  When the instructions aren't heard clearly, the yoga student is for a moment, directionless, or even worse, misunderstands the next instruction, and realizes it after already entering the wrong pose.  When directionless, you are distracted and preoccupied with trying to find out the next pose, or puzzling at what the instructor said.  In this manner, at least, entering the wrong pose is slightly better.  There is less distraction and querying, and the easy decision is to just immediately switch poses, albeit at a loss of time and tempo and therefore depth within the next pose.


So I've been doing yoga daily for over a week straight now.