Show Me A Picture Of An Eye Chart
An eye chart is a tool used by eye care professionals to measure visual acuity. It consists of rows of letters or symbols that decrease in size as they move down the chart. The patient is asked to read the letters or symbols from a specific distance, usually 20 feet away. The smallest line that the patient can read accurately determines their visual acuity. In this article, we will explore eye charts in detail, and show you some pictures of eye charts.
History of Eye Charts
The concept of an eye chart was first introduced in the late 1800s by Dutch ophthalmologist Hermann Snellen. He developed the first standardized eye chart, which is still widely used today. The Snellen chart consists of 11 lines of block letters, with the largest letter at the top and the smallest letter at the bottom.
Over the years, other eye charts have been developed, such as the Tumbling E chart and the Landolt C chart. These charts use symbols instead of letters, making them useful for patients who cannot read or recognize letters.
Types of Eye Charts
There are several types of eye charts used by eye care professionals. The most common ones are:
- Snellen chart
- Tumbling E chart
- Landolt C chart
- Jaeger chart
- LogMAR chart
Snellen Chart
The Snellen chart is the most widely used eye chart. It consists of 11 lines of block letters, with the largest letter at the top and the smallest letter at the bottom. The letters on each line are progressively smaller than the previous line. The patient is asked to read the letters from a distance of 20 feet away.
Tumbling E Chart
The Tumbling E chart is similar to the Snellen chart, but instead of letters, it uses the letter E in different orientations. The patient is asked to identify which direction the E is facing.
Landolt C Chart
The Landolt C chart uses the letter C in different orientations. The patient is asked to identify which direction the opening of the C is facing.
Jaeger Chart
The Jaeger chart is used to test near vision. It consists of paragraphs of text in different sizes. The patient is asked to read the text from a distance of 14 inches away.
LogMAR Chart
The LogMAR chart is a more recent eye chart, developed in the 1980s. It uses letters that are designed to be more uniform in shape and size than the letters on the Snellen chart. The patient is asked to read the letters from a distance of 4 meters away.
Conclusion
Eye charts are an important tool used by eye care professionals to measure visual acuity. There are several types of eye charts, each with its own unique design and purpose. If you have concerns about your vision, it is important to schedule an appointment with an eye care professional.