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The article gives advice on measuring or assessing visual acuity (VA) in a consistent manner. Particular focus is given to indications for assessing VA, as well as the equipment needed. Topics discussed include the importance of ensuring good natural light on the Snellen chart, patient positioning...
The Snellen test uses a chart that contains letters or symbols. These letters are arranged into rows — each row becoming progressively smaller and smaller down the chart. To measure visual acuity, you'll be asked to stand approximately 20 feet away from this chart. As you cover one of ...
It’s called a Snellen chart, and we’ve been using it to measure visual acuity since the 1800s. If your visual acuity is determined to be 20/20, it means that at 20 feet, you can see what a person with normal vision can see at 20 feet. But, if you have 20/40 vision, it me...
Many vision screening tests performed in schools are confined to the Snellen chart. Developed in 1862 by the Dutch ophthalmologist Hermann Snellen, the chart is used to measure visual acuity, defined as the visual ability to resolve fine detail. ...
Visual acuity ‘Acuity’ is a measure of the resolving power of the eye – the ability to discriminate between two points. Distance charts that you should be comfortable with include the Snellen and the LogMAR. Near vision charts that you should be comfortable with include the N-series. In ...