The Hess Test: How does it work and why is it administered?

The Hess Test: How does it work and why is it administered?

The Hess Test involves anaglyph glasses and a grid attached to a wall or screen in front of the patient. The purpose of this test is to get an idea of whether or not the eyes align absent of any exterior reference points and thus without any compensation ability the patient might usually be employing. During the test the patient is wearing anaglyph glasses while watching the grid. Somewhere within the grid a red light will illuminate itself or will be projected by the clinical assistent. The patient has a green laser pointer…Read more …
Herb Black: Geologist turned Optometrist after 3D vision discovery

Herb Black: Geologist turned Optometrist after 3D vision discovery

"I had never had 3D vision, but didn't really know it until I was an adult. I noticed I had no 3D vision because, as a geologist, my colleagues would look at stereo pairs of aerial photos, fuse them in free space or with a viewer, and see 3D. I could not do that at all. It was a real mystery to me how they could do that, especially in free space without a 3D viewer. My daughter had binocular vision problems as a child and was helped tremendously by optometric vision therapy here in…Read more …
INTERVIEW: How Bill Johnston discovered stereo vision at the age of 70

INTERVIEW: How Bill Johnston discovered stereo vision at the age of 70

REMINDER: When reading on a desktop, you can have the article read to you by selecting the desired paragraph and clicking on the little speaker icon. I first learned about Bill Johnston when, in early 2014, he posted this message in one of the amblyopia and strabismus Facebook groups. “My lazy eye turned on on New Year’s Day. I don’t have amblyopia anymore and I do have depth perception for the first time in my life. The whole world is more beautiful than I ever could have imagined. I will be 70 years old in the…Read more …
What role do various brain areas play in vision? – Part 1

What role do various brain areas play in vision? – Part 1

After previously writing about the basal ganglia and the crucial role they play in vision and brain plasticity, I was intrigued and wanted to understand what implications binocular vision dysfunctions have for the brain as a whole more thoroughly. In this post, part 1, I will introduce more related brain areas involved in visual processing one by one. In part 2 I want to provide a more cohesive view of what is told in part 1, a illustrative summary if you will, explaining how this relates to earlier discoveries and my own experiences…Read more …
How to prevent a strabismus or double vision burnout

How to prevent a strabismus or double vision burnout

Perception is a constant flow of action and reaction. Your own actions, even unconscious ones like moving your eyes, and other events beyond your control shape your perception and your perception shapes your actions. Both are intimately linked in a lifelong perceptual stream. Once your mind is infected with the idea that acquiring 3D vision is possible, a heightened sense of self-awareness, a lot of patience and supportive people can avoid a total double vision burn out. You can divert the visual stream to a better place, but it’s similar to steering the titanic away…Read more …
Session 43: A picture is worth a thousand words

Session 43: A picture is worth a thousand words

Last week I was a bit sick and nothing seemed to work but this week things seem to be better. Sometimes it would just be easier to be a robot and shut down the stream of consciousness, wouldn't it? Either way it's better not to accumulate too many diseases at once. :D In today’s session we did some of the usual stuff... The rotoscope, balancing on the rail with various prism glasses and one exercise we did a few times before. This exercise consists of standing upwards, looking though some kind of holder…Read more …

Strabismus is less a problem to be cured than a problem to be controlled

Surgery's lack of success in achieving good binocularity and the troubling trend of repeated surgeries and recurrance of the strabismus has predicably lead surgeons to have low expectations of the the results of strabismus surgery. In a recent journal article, one surgeon noted that "strabismus is less a problem to be cured than a problem to be controlled, with the minimum number of surgeries": Simon, John W. Complications of strabismus Surgery. Current Opinion in Ophthalmology. 2010. 21: 361-366. More on: http://www.visiontherapy.ca/strabismustreatment.htmlRead more …
Analysis of strabismus and its symptoms, patient prognosis and success rate of Vision Therapy

Analysis of strabismus and its symptoms, patient prognosis and success rate of Vision Therapy

My awesome friend and medical student Stephanie Johanns found the success rates of Vision Therapy for me through a medical search engine. She got me the Optometric clinical practice guidlines for the care of patients with accommodative and vergence dysfunction published by the American Optometric Association. She wanted me to have this scientific text aside from inspiring stories like Susan Barry's. 'Accommodative and vergence dysfunction' is a fancy phrase for (manifest as well as latent) strabismus, which in turn is a fancy word for being cross-eyed. This text, aside from being a bit technical, contains a positive…Read more …