In the case of the traditional Snellen chart, the optotypes have the appearance of block letters, and are intended to be seen and read as letters. They are not, however, letters from any ordinary typographer's font. They have a particular, simple geometry in which:

The Snellen Chart may be recognized as the familiar block-lettered “EFPTOZ” poster hanging in many ophthalmology and optometry offices. To measure distance visual acuity using the Snellen standard, patients stand 20 feet – the numerator, or top number in …

2013年5月24日 · The EFPTOZ chart (pictured here) has practically become iconic, undermining its medical value, Colenbrander says. A recognizable eye chart is not a very useful one.

2021年10月11日 · Download this printable Snellen chart to do your own vision screening. Just print the chart, hang it up on a wall, measure the proper distance from it and start reading. Note: The size of the chart was adjusted for printing purposes, so you should place it 10 feet away from you rather than 20.

1995年8月9日 · "It's our basic tool for checking central visual acuity - checking the sharpness of the vision that's directly in the center of the retina," says Judy Hustead, an ophthalmologist with Charlotte Eye...

2015年10月20日 · When you go for an eye exam, your eye doctor uses an eye chart to measure how well you see at a distance compared with others. The classic example of an eye chart is the Snellen eye chart, which was developed in the 1860’s by Dutch eye doctor Hermann Snellen, but there are others.

1995年7月20日 · EFPTOZ. Wasn’t that a disco hit back in ’74? Not by a sight. Those letters form the first lines on the most popular poster of all time: The eye chart.

2024年4月11日 · Comprehensive eye exams are essential for maintaining eye health. What Does the Eye Chart Test? Photo by Skyler Ewing. Have you ever wondered about the eye chart …

2024年2月14日 · When you visit the eye doctor for a checkup, you may be asked to read an eye chart. The chart measures your visual acuity, or sharpness of vision. If you don’t wear glasses or contacts, your eye doctor will use the results to find out whether you need them. If you wear corrective lenses, the results will show if your prescription needs to change.

2014年3月21日 · Snellen, a Dutch ophthalmologist, developed the Snellen chart to measure a person’s visual performance against an objectively defined and repeatable reference standard. At this point, there were only reading tests that relied on whatever fonts were available at the local print shop, but no objective standards.