Certified Ophthalmic Assistant Practice Exam

What type of vision is most commonly tested using a Snellen chart?

1. Near vision

2. Distance vision

3. Color vision

4. Contrast sensitivity

The correct answer is: Distance vision

The Snellen chart is specifically designed to measure distance vision. It consists of letters or symbols arranged in rows of decreasing size and is typically viewed from a standard distance, usually 20 feet. This method allows the eye care practitioner to determine how well a person can see at a distance, which is crucial for assessing overall visual acuity. Testing near vision usually involves different charts designed for closer distances, often using smaller text or specific reading material. Similarly, color vision and contrast sensitivity are assessed through various tests that focus on different aspects of visual function and do not utilize the Snellen chart. Therefore, the primary purpose of the Snellen chart aligns directly with testing distance vision.