I’ll start with a bit of background. I’m Ben’s younger brother, Nick, and I was very keen to see how his software works. Other than mild short-sightedness, I do not think there is anything wrong with my eyes. Sitting in Ben’s office, I noticed a 3D magic eye picture on the wall, and commented that I have never been able to see the 3D image, even though I had a book full of pictures as a child. I tried it again; no success.
We started with the triangles [Ben : the standard conflict scene] and they were overlaid as expected. When we got to the cyan and yellow semicircles within white circles, I noted the horizontal offsets between the semicircles, but everything was flat. There was no depth, and the outer white diamond that encloses the entire image was square.
I noticed that I could consciously fade either the cyan or yellow semicircles to being invisible (and control the brightness at levels in between) but I really didn’t understand the instructions, which were to select the circle that was ‘closest’. Everything was still flat and I ended up choosing the semicircles that matched closest. This was not right and I kept selecting the wrong circle!
I then tried moving my focal distance (the point at which both eyes converged) closer then further away and noticed that I could move the semicircles sideways to get them to join into a full circle. By doing this several times for each pair, I could figure out which circle was ‘closest’ entirely by feeling my eye muscles. Did this circle ‘feel’ closer because my eyes were more cross-eyed?… But this wasn’t particularly sensitive and sometimes circles were very similar and I had to adjust my eyes several times on each circle to feel a difference. Still flat though!
Then I looked into the black space in the middle of the screen, relaxed my eyes (I was probably staring into the distance) and BAM, I could see the four circles were distorted and had depth. Also, the outer diamond was bowed toward me. Keeping my eyes on this black space, it was easy to judge the relative distances of the circles. After a few rounds, I was able to look around the image and maintain the 3-dimensional illusion at all times.
I guess the purpose of this post is that I want to share my discovery that seeing the image in 3D is not necessarily automatic. It took me a few stages for it to happen: manually varying my distance of focus and figuring out this distance based on my eye muscles, then staring into the middle of the screen before the 3D became apparent. Perhaps I have been unable to separate the two process of focussing (which is done with the lens in each eye) and depth perception (which uses the two eyes together). Certainly, when trying the 3D magic eye pictures my eyes have been staring into the distance (correct!) but my focussing was too (incorrect!) so the image was just a blur. Time to find that old book! I hope this helps someone. Best of luck.
Here I am in Berlin, with the Prototype team and a poster. Interesting discussions have been had, but most interesting for me, has been the interest in the project from conference participants who have noticed the strabismic eyes and come over to try it out.
As usual, each person displays subtle but significant differences in the way they perceive the world.
EyeSkills Feature demonstration / user test with Cliff W – 02.09.2018
This was intended as a quick test of new features, but it generated some very interesting ideas and insights. Here, we describe the order of the scenes tested, insights won, and finally, draw conclusions. Cliff has alternating strabismus.
Each user test is an exciting event. Each user test throws up at least half a dozen “aha” or “why didn’t I think of that” moments, driving on and further inspiring development. In our most recent user test (yesterday evening with Mr R) there were some obvious but useful minor improvements we could make to help practitioners, and a couple of major issues were also raised about determining what the participant is really perceiving.
When building software, one is creating a simplified model of reality, capturing those parts which are relevant to achieving the system goals. This model is not generally not built to be passive, it should then interact with reality to alter the nature of reality. It’s an interesting feedback loop called “active modelling”. If we don’t iteratively test as we design and build, we will inevitably design systems that fail to capture reality and fail to then interact with it as desired. This is particularly true of systems which interact with people. Continue reading “Why is designing EyeSkills difficult? – a quick note”
What a wonderful test. Mr R has alternating strabismus, and a very strong suppression. The Binocular Suppression scene is now designed well enough that it not only demonstrates the suppression switching on very well (by introducing conflict), but allows us to find that breakthrough point where – despite the suppression – Mr R can see both (despite the conflict). The eye misalignment worked well. Mr R couldn’t see any depth in the depth test – which was precisely what I expected at this stage from him. Unfortunately, there was ambiguity in the alternating fusion scene and the eye straightening scene, because it wasn’t clear enough if both eyes were active or not.
I will make a series of improvements which allow us to interactively introduce/remove conflict in these later scenes, and provide visual cues so it is clear without a doubt, what they participant is actually experiencing from their descriptions of what they are perceiving.
This is a quick note about some more user tests we ran, this time with two ladies in their forties and fifties.
We had our vision therapist with us, who ran both through a series of standard tests. In both cases, neither could use both eyes simultaneously!
As soon as they were in the VR environment, suppression was broken. We believe the cause was the “low conflict” nature of the environment they were looking at (mostly black backgrounds). I apologise for not having the time for writing up the full test, but we have – more importantly – implemented the ability to place more of our calibrations/test into and out of conflict in the recently finished second iteration of our prototype.
In the next phase of testing, we will revisit this phenomenon in more detail!