What is Depth Perception Testing?

Depth perception (or stereo) testing checks the ability of the patient to perceive the distance to an object as well as see the object in three dimensions. Depth perception problems are often related to a patient’s eyes not working together due to an eye turn, a prescription difference between the eyes, or amblyopia (lazy eye).

How to Complete Depth Perception Testing

Depth perception is usually completed on children ages 1 through 16 during their annual exam and is tested through one of two methods: Lang or Randot.

The Lang test, which is normally completed by the doctor, is used for very young children and non-verbal patients. It looks like this:

The test is completed using the stereo card that is housed in the red case.

To complete this test the stereo card is held in front of the patient while observing the patients eye/hand movements. If a patient with normal depth perception looks at the card they will see images of a cat, a star and a car (see below)

A patient with abnormal depth perception will not see any images (see below)

During testing, the doctor will observe if the patient looks at each of the images or reaches out to touch each image. They will usually report that the patient “looked at” or “touched” either the cat, star, car, or all three which should be recorded in the patient record.

The Randot test, which is normally completed by the OA, is used for older children/adults and looks like this:

Have the patient will put on the special glasses on when completing the test. A patient with some level of depth perception looking through the glasses at the book will be able to see images standing out from the background.

There are two sections to the booklet, one on the right side of the booklet, the other on the left. Starting with the rectangles on the right side, the patient will report what they see. With normal depth perception they should be able to see the shapes inside most of the rectangles (there are two rectangles without images). Moving to the left side, ask the patient which animals are standing out in rows A through C. If the patient gets all these correct, ask them which circles in each row seem to be lifting off the page, starting with row 1 and moving toward row 10. As the patient moves through the book the images will become more and more difficult to perceive, stop when the patient is no longer able to give a correct answer and reference their last correct answer to the answer key on the backside of the book. The last correct answer they give will correspond to a grade in “seconds of arc” which will be recorded in the patient record.

The following video gives an example of what completing the randot test looks like.

How to Record Depth Perception Testing

Depth perception testing is recorded in the Stereo Acuity boxes in the middle of the Binoc tab.

Testing is always completed at near so be sure to use the “near” boxes.

If the Randot test was used and the patient was able to see all shapes on the right hand side, all animals, and was able to see up to the 8th circle (missing the 9th), referencing the answer key on the back of the randot, you would find the score to be 30 seconds of arc.

You would record this as shown below.

What is Color Vision Testing?

Color Vision testing assesses the patient’s ability to differentiate between different shades of color.

How to Complete Color Vision Testing

Color Vision testing is usually completed on all males ages 5 to 16 during their annual exam. It should also be completed on females ages 5 to 16 if it is the first time we are seeing them for a full exam (this will not need to be repeated at subsequent exams). There are several different color vision screening tests we use; the most commonly used is called “Waggoner” and looks like this:

To perform the Waggoner color vision screening, holding the booklet at a normal reading distance from the patient, have them observe the cards and report what they see. A patient with normal color vision will be able to see shapes on each card. A patient with abnormal color vision will be able to see either some of the shapes or none of the shapes. If the patient is unable to see several of the shapes, you would report to the doctor that their color vision screening was abnormal.

How to Record Color Vision Testing

Color vision testing is recorded in the middle of the workup tab.

If a Waggoner color vision screening was performed and the patient was able to see all shapes on all pages, this is how it would be recorded in the chart:

Here’s a video on how to enter color vision and stereo testing findings.

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