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MD Doc
MD Doc, Dr
Category: Eye
Satisfied Customers: 8123
Experience:  MD since 1994
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I have to take an eye test and I'm a bit stressed so I was

Customer Question

I have to take an eye test and I'm a bit stressed so I was hoping to find more info about taking depth perception tests that cover stereoacuity, cover test, & compensating vergence measures
JA: When was the last time you had your eyes checked? In general, how has your vision been lately?
Customer: last check was about 3 months ago for a job interview...vision is good. I do have depth perception issues in my eye history
JA: Anything else in your medical history you think the doctor should know?
Customer: I had eye surgery on my left eye when I was 5 (40 years ago) and over time my dominant eye (right) has become more blurry requiring glasses
Submitted: 1 month ago.
Category: Eye
Customer: replied 1 month ago.
The test also needs to cover Horizontal Visual Field (in degrees)
Expert:  MD Doc replied 1 month ago.

Hi,

Depth perception means the ability to see things in three dimensions – length, width, and depth. Depth perception might be hampered in patients of Amblyopia, Strabismus, Suppression and Stereopsis. Stereovision is how each eye may see an object from different angles, but combines these angles to give us a 3D image. Since, you have had a surgery in left eye at early age, I presuming it was for starbismus and also despite the surgery, you do not have proper vision in the said eye. This might have lead to issues of depth perception, since one eye is dominant (right eye) and one has suppressed vision (left eye).

So, in the above mentioned tests, The ability of both your eyes together able to see an object in 3 Dimensions will be tested.

Hope this information is helpful

Customer: replied 1 month ago.
Actually I need to know what those tests consist of so I can do my best on them.
Expert:  MD Doc replied 1 month ago.

Hi,

There are a lot of variations of the depth perception tests used. The result is usually not dependent on the practice done by a patient. The results are based on whether both your eyes have a binocular vision or not.

The most commonly done is Random Dot 2 Stereo Acuity Test which uses polarized glasses. The test is composed by a 3 × 4 boxes grid, and in each row, three boxes contain a Symbol at a fixed disparity (500, 250 and 125 seconds of arc, respectively), and the fourth contains random dots only. Users must report for each box if they perceive an object at a different depth from the background, and they must identify the object shape. The shape can be a heart, hut, apple etc
The stereo acuity test is based on a graded circle test composed by 12 boxes, arranged in a 3 × 4 grid. In each box, three circles are depicted side by side, with only one circle placed differntly. The set of disparities ranges from 400 to 12.5 seconds of arc. The circles are drawn using a black and thick border. Starting with the largest disparity in a descending scale, the patient is asked to identify the circle at each level that appears closer than the others. The last level for which the subject answers correctly is considered to be the level of stereoacuity.

compensating vergence measures is done by the clinician. This is done by adding prism lenses on the trial frame for glasses and then measuring the amount of prism needed for each eye in the subject

Cover test is again done by the clinician by shining a torch in your eye and covering-uncovering each eye by turn to see any deviation present in either eye and if present how much is the deviation.

I am attaching photo of the random dot 2 test used for stereoactivity

Hope this information is helpful

Regards

Expert:  MD Doc replied 1 month ago.

Please let me know if you have any additional questions or if you want to discuss this further. And please take a moment and kindly click a positive rating (preferably 5 Star/Excellent) to credit for the time & effort put by me in answering your health question, and this is the only way I will be credited for my service to you. If you have follow-up or additional questions you can ask them after the rating too!

Cheers

Expert:  MD Doc replied 1 month ago.

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Regards