Illinois Vision Certification Practice Test

A stereoscopic test instrument can simulate test distances of what for distance?

1. 30 feet

2. 15 feet

3. 20 feet

4. 25 feet

The correct answer is: 20 feet

A stereoscopic test instrument is designed to assess binocular vision and depth perception by simulating different test distances. The correct choice, 20 feet, is significant because it aligns with standard practice in optometry for distance vision testing. Generally, visual acuity tests are conducted at 20 feet to provide a realistic assessment of how well a person can see at typical viewing distances in daily life. When simulating test distances, this specific measurement is critical to maintain consistency with established norms for vision testing. In comparison, options like 15 feet or 25 feet, while potentially relevant for some assessments, are less commonly used for the standard distance visual acuity measurements, which emphasizes why 20 feet is the most relevant distance in this context. Additionally, 30 feet is outside the commonly accepted range for most practical vision tests, further clarifying the reason why 20 feet is the optimal simulated distance.