I'm copying part of a report from http://www.livescience.com/health/080902-zen-meditation.html. Please see the original link for the full article.

There is a very strong relationship between thoughts and intraocular pressure. I have been writing about it here on FitEyes.com for several years. One's state of mind is one of the most important factors in managing intraocular pressure. Serene Impulse is the best technique I have found for putting my mind and body into the state of restful alertness that promotes efficient activity and low eye pressure. Even a few seconds of Serene Impulse practice can often immediately reduce my eye pressure. However, it is most useful to me due to its ability to reduce my supine IOP at the peak time of day (early morning) when I practice Serene Impulse the prior day.

Serene Impulse is a mind-body skill that promotes health and inner peace. Serene Impulse works strongly at the level of the physical body, including the heart. Meditation is different in that it usually works more at the level of the mind (to make a generalization).

Although I have not tested all meditation techniques, of those I have tested, none were effective in reducing my intraocular pressure.

However, understanding Zen meditation is useful background for understanding the research I'm doing on consciousness and intraocular pressure. Therefore, I want to share part of the following article with readers of FitEyes.com. (I have edited this version.)

In particular I like the discussion of thoughts in this article. Anyone with POAG should be aware of the relationship between thoughts and IOP. Even without using any formal meditation technique, if one effortlessly allows thoughts to settle down or temporarily cease, one will have succeeded in reducing one's IOP in my experience. The catch is that most people without meditation training cannot allow thoughts to stop effortlessly. Most of us can't go for even 60 seconds without thinknig. And when we try, we strain. Such trying will only raise IOP.  Without further comment, here is the article on Zen Meditation research.

Study: Zen Meditation Really Does Clear the Mind

By Charles Q. Choi, Special to LiveScience [Edited for FitEyes.com by David]

Zen meditation discourages mental withdrawal from the world and dreaminess, and instead asks one to keep fully aware with a [easy, watchful] attitude. Typically one focuses on breathing and posture and [witnesses thoughts as they arise without engaging in the thoughts]. Brain scans now show that Zen training leads to different activity in a set of brain regions known as the "default network," which is linked with spontaneous bursts of thought and wandering minds. [Image credit: Dreamstime] var related_images = new related_module();

The seemingly nonsensical Zen practice of "thinking about not thinking" could help free the mind of distractions, new brain scans reveal. [It might be more correct to say the practice involves allowing thoughts to occur without engaging in them. One witnesses thoughts. It is not an effort to stop thinking.]

This suggests Zen meditation could help treat attention deficit and hyperactivity disorder (so-called ADD or ADHD), obsessive-compulsive disorder, anxiety disorder, major depression and other disorders marked by distracting thoughts.

In the last decade, there has been a resurgence of scientific research into meditation, due in part to the wide availability and increasing sophistication of brain-scanning techniques. For instance, scientists recently found that months of intense training in meditation can sharpen a person's brain enough to help them notice details they might otherwise miss.

"It is important that this type of research be conducted with high scientific standards because it carries a long-standing stigma — perhaps well-deserved? — of being wishy-washy," said researcher Giuseppe Pagnoni, a neuroscientist at Emory University in Atlanta. "Constructive skepticism should always be welcomed as a great sparring partner."

Pagnoni and his colleagues investigated Zen meditation, which Pagnoni himself has practiced while studying for his doctorate in Italy.

The Zen of Zen

[Over time, with regular daily practice, the mind settles down and one] becomes aware of otherwise unconscious behaviors and preconceived notions and hopefully gain insights into oneself, others and the world.

To see what effects Zen meditation might have on the brain, scientists compared 12 people from the Atlanta area with more than three years of daily practice in Zen meditation with 12 novices who had never practiced meditation.

The researchers "had to screen — and discard — a number of colorful characters who during the interview declared that they were meditating regularly by screaming in a towel while stomping their feet on the ground, or that they were communicating frequently with beings of other planets," Pagnoni recalled. "Such are the unexpected joys of this research!"

As the volunteers had their brains scanned, they were asked to focus on their breathing. Every once in a while, they had to distinguish a real word from a nonsense word displayed at random times on a computer screen and, having done that, promptly try and focus on their breathing again.

Their scans revealed that Zen training led to different activity in a set of brain regions known as the "default network," which is linked with spontaneous bursts of thought and wandering minds. After volunteers experienced in Zen were distracted by the computer, their brains returned faster to how they were before the interruption than novice brains did. This effect was especially striking in the angular gyrus, a brain region important for processing language.

"The regular practice of meditation may enhance the capacity to limit the influence of distracting thoughts," Pagnoni said.

The research, funded by a National Institutes of Health grant, is detailed online Sept. 3 in the journal PLoS ONE.