What does 2020 vision mean

When you have an eye test with a Snellen chart, you will typically be sat 20 feet away from it. If you can read this, but nothing smaller on the chart, you are considered legally blind and see from 20 feet what a person with normal visual acuity can read from feet. Each line on the Snellen eye chart corresponds to better visual acuity as you go further down. Prescriptions are measured in dioptres, which is a unit of measurement for refractive errors.

Somebody with a The higher your prescription number is, the more trouble you will have seeing clearly without visual aids. Optometrist test your visual acuity using the Snellen Eye Chart. The Snellen Eye Chart is used to test visual acuity.

It consists of displaying letters of progressively smaller sizes. The common Snellen chart has 11 lines of block letters. As you move down the chart each row not only gets smaller, but also increases in number of letters. The visual acuity test is just one aspect of the typical eye exam. Patient Portal.

Order Contacts. Hearing Loss? Vision Testing Visual acuity is usually measured with a Snellen chart.

Most printed material is at this level. News Headlines are this size. Join the AOA today! Vision and Vision Correction. Will clarity of vision vary with distance? Find a Doctor of Optometry. Zip Code. Advanced Search. Share This. Related Articles. Healthy Vision and Contact Lenses Safe contact lenses use provides an effective form of vision correction. Types of Contact Lenses There are many types of contact lenses, each with its own advantages and disadvantages.