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Home » What's New » Costa Mesa, CA Vision Exams: Exploring the Eye Chart

Costa Mesa, CA Vision Exams: Exploring the Eye Chart


Ever ask why 20/20 is the benchmark for ''perfect'' vision and what it really means? 20/20 vision is a phrase used to describe normal visual acuity or clarity of vision. That is to say that someone with such vision will be able to clearly see an object at a distance of 20 feet that the majority of people are expected to be able to see from that distance.

In cases of individuals that don't have 20/20 visual acuity, the number is determined based on the first point at which they are able to see clearly, in relation to what is normally expected. As an example, 20/100 acuity means that you have to be at a distance of 20 feet to see what a person with normal vision can see at 100 feet away.

An individual with 20/200 visual acuity is considered blind, legally however, they can often see normally by using glasses or contacts or by undergoing LASIK if they qualify.

A typical vision test is performed by using an eye chart most commonly the familiar Snellen eye chart created by Hermann Snellen, a Dutch eye doctor in the 1860's. While today there are many variations, the chart generally has 11 rows with uppercase letters which get smaller in size as they move toward the bottom. The chart begins with the capital letter - ''E'' with the addition of more letters on the lines as they get smaller. During the eye exam, the eye doctor will look for the smallest line of letters you can read. Each line is given a rating, with the 20/20 row typically being assigned forth from the bottom. In cases in which the patient can't read, such as young children or handicapped persons, the ''Tumbling E'' chart is employed. Similar to the regular Snellen chart, the ''Tumbling E'' is composed of only the capital letter E in different rotations. The patient uses their hand to point to the right, left, top or bottom to show which direction the E is pointing. Both charts should be positioned 20 feet away from where the patient is viewing it.

Despite common conception, 20/20 eyesight does not mean an individual sees perfectly but rather that they see well at a distance. Total eyesight includes many other important skills such as side or peripheral vision, depth perception, focus for near vision, color vision and coordination between the eyes to name a few.

While an eye exam with a Snellen chart can establish whether you need glasses to see far away it doesn't provide the optometrist a full perception of the complete status of your eyes and vision. It's recommended that you still schedule a yearly comprehensive eye exam which can diagnose vision-threatening conditions. Call our office now to schedule a Costa Mesa, CA eye exam.


COVID-19 has been and continues to be an ongoing trial for all of us. During this unforeseen time, we ask kindly for your understanding and compliance to the CDC guidelines. In order to decrease the chances of contraction, we are allowing only one parent to accompany their child during the examination. We appreciate your patience and understanding.

We also want to inform you of the new additional symptoms of COVID-19 that have been added to the previous symptoms as potential indicators of having COVID-19:

New symptoms:             Congestion/runny nose

Previous symptoms:       Headache
                                            Dry cough
                                            Shortness of breath
                                            Sore throat
                                            Muscle/body aches
                                            New loss of taste or smell

Please be aware that a person does not have to have all of these symptoms but anyone or multiple symptoms can be an indicator of having COVID-19. If you or any family members are experiencing any of the above symptoms, we kindly ask that you reschedule your appointment and contact yourprimary care provider. It is best to reschedule your appointment with us after being symptom-free for14 days.

We at South Coast Optometry truly appreciate each and every one of you as a person and value your trust in us to take care of your most precious eyes. As always, we will continue to closely monitor the COVID-19 situation and communicate any and all changes through our website, Again, we truly appreciate your understanding and support during this unprecedented time and look forward to seeing everyone soon!


Dr. Daniel E. Quon, O.D., and The Entire South Coast Optometry Team!!!


Until further notice, we are only seeing essential care patients. Our hours are:
Monday: 10:00 AM to 7:00PM
Tuesday: Closed
Wednesday: 10:00 AM to 7:00 PM
Thursday: 9:00 AM to 6:00 PM
Friday: 10:00AM to 6:00 PM
Saturday: 9:00 AM to 5:00 PM

We now offer TeleHealth consultations, Call (714) 540-2020 to schedule a time
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