You can use stereopsis testing equipment to know. You will find below some vocabulary to help you while learning about the stereopsis tests developed and sold by visionassessment and described here.
The visual perception of depth, or the ability to see three-dimensionally. For this to occur, the person must be binocular. Also : Awareness of the relative distances of objects from the observer, by means of binocular vision only and based on retinal disparity.
Details about Stereopsis are available in chapter 2 of our "Digital Stereoscopy" book.
A polarized stereogram is a pair of polarized images at 90° from each other. When viewed through polarizers it presents one image to one eye and another image to the other eye.The Vectograph is a chart based on this principle in which almost one half of a chart is seen by one eye and almost the other half by the other eye. It is used to detect stereopsis defects. Read the vectogrma definition in thefreedictionary here.
The TITMUS test
The Titmus stereotest consists of various vectograms, including one with a stereoscopic pattern representing a housefly, to establish whether the patient has gross stereopsis.