What is 20/20 Vision?

San Francisco, Oakland, and San Jose, California

You may know that it is good to have 20/20 vision, but you may not know exactly what that means. At the Laser Eye Center of Silicon Valley, our goal is to help you restore the vision of your youth, at least as much as medically possible. In order to help you appreciate the outcome of your vision correction it is a good idea to know what 20/20 vision is and have realistic expectations of your LASIK treatment.

Visual Acuity

How well you see is called your visual acuity, or VA. 20/20 vision is considered normal vision. It means that at a distance of 20 feet, you can identify the black characters on a white background of a standardized eye chart. Twenty feet is used because that is the distance where your eye focuses when looking at infinite space.

If you see twice as well at 20 feet, you have 20/10 vision; if you see half as well then you have 20/40 vision. The goal of most treatment options, including glasses, contacts, or surgery like LASIK or PRK is to get you closer to 20/20 than where you are currently.

If you cannot reach a visual acuity of 20/200 with your best eye, even with the best available glasses, then you are considered legally blind in the United States.

Snellen chart

If you ever wondered about the typical eye chart used by most ophthalmologists, it is called a Snellen chart named after a Dutch ophthalmologist named Herman Snellen who developed it in 1862. The traditional chart has eleven lines of block letters. The top line typically uses the letters E, H, N or A. The letters on each row decrease in size and there are more letters in each line. The lowest line you can read on the chart indicates your visual acuity for each eye.

Dominant eye

Most people have one eye that has a better visual acuity than the other does; however, the visual acuity does not necessarily correlate with your dominant eye. There are several tests Dr. Gary Kawesch may perform to determine eye dominance. Discovering your dominant eye, should you have one, is important when considering monovision LASIK or RFL. The dominant eye is usually corrected for distance vision while the non-dominant eye is left alone, or corrected for near vision.

Serving the residents of San Francisco, Oakland and San Jose, Dr. Gary Kawesch and his team of experienced optometrists and friendly staff can help you see clearly once again. Please contact our office today for an initial consultation.

1.800.725.0740