If you are not part of the McGill Psych 100 class, please use this link to access the correct web pages for your 3D glasses.

This 3D vision test is a research study being conducted by Prof. Robert Hess of the Department of Ophthalmology and Prof. Jeremy Cooperstock of the Centre for Intelligent Machines of McGill University.

We are conducting this brief, informal experiment to assess the quality of 3D vision (stereopsis) of the general population. Please note that your participation is completely voluntarily. The request for your email address is only so that we can contact you to request your participation in a possible follow-up laboratory test. Your address will not be shared with anyone outside of the research group conducting this study.

The test itself should only take you a few minutes. At the end of the experiment, your 3D vision or stereopsis score will be calculated and displayed to you, along with some facts about 3D vision.

For further information about 3D viewing, please see this helpful Viewing 3D on TV: Questions and Answers page from the CBC.


First, we need to know the size of your monitor. These typically range between 7-12 inches for netbooks, 10-17 inches for laptops, and 15-24 inches for desktops. If you're not sure of your monitor size, please enter the make and model number in the other box.

If you know, or have measured, the size (diagonal) of your monitor, please enter it here:
or, if you know the make and model of your monitor, enter it here:


Your height is needed to help approximate your viewing distance from the monitor.

Height in centimeters cm, or
or, in feet and inches ft. in.

Sitting Distance

Ideally, if your monitor is larger than 15 inches, you should be two arms-lengths away, as shown in the image to the left. Otherwise, the test will be too easy and we won't be able to measure your stereo vision properly.
However, if you can't reach the mouse from that distance, you can sit one arm-length away, as shown here.

How far are you sitting from the monitor? 2 arms-lengths
1 arm-length

Age, Email, and Corrective Eyewear

For analysis purposes only, kindly let us know your age and whether you use eyeglasses.

Your age
Your email
Do you regularly use any corrective eyewear (eyeglasses, contact lenses)? yes no

Get ready...

In the following screens, you will be presented with a number of random dot stereograms in which a box in the center appears either in front of or behind the rest of the image. At first, it should be easy to see the box, but this will become more difficult as you continue the test.

After you've looked at the image for a few seconds, please click on the appropriate button below to continue the test.

Please do not try to move closer to the monitor during the test as this will invalidate the results.

Now put on your 3D glasses with RED and GREEN lenses... you are ready to begin.