He has also lectured to his optometric peers at provincial continuing education courses for the Alberta Association of Optometrists.ĭr. His lectures are known for being very educational and extremely fun and interactive. Hyde has performed well over 100 classroom presentations about light, optics, anatomy, and ocular health to local high schools, junior high schools, and elementary schools. Hyde has a passion for specialty contact lenses, advancements in ocular technology, pediatric eye care, ocular disease, and being an academic lecturer and presenter. Much of the information in this blog post was gleaned from Dr. Click here to schedule your appointment today! Every time you write “2020” let that be a reminder to visit the optometrist and congratulate them on the year of perfect vision. An comprehensive eye exam is much more than seeing if you can read the 20/20 line. Annual eye exams are extremely important to evaluate eye health and look for any early signs of these damaging conditions. Read more information here about proactive eye care. There can be preventative measures to slow and even stop progression but in some cases the vision deterioration is irreversible. Often these conditions are progressive- meaning the vision degenerates more and more over time. These conditions include cataracts, macular degeneration and even extreme dry eyes. Unfortunately certain eye conditions will prevent correction to 20/20 even with corrective lenses in glasses. Using this reference will catch most visual disorders such as farsightedness, nearsightedness and astigmatism. There are even smart phone apps that can measure visual acuity. McEathron measuring visual acuity The quest for perfect visionĪs discussed above, 20/20 visual acuity is a measured by eye doctors. The resulting numbers represent the strength of lenses needed to help you see 20/20. You’ll remember this from the eye exam when the doctor asks which is better one or two? and moves knobs or buttons until you can read the 20/20 line. A more comprehensive description of vision would include eye tracking ability, contrast sensitivity and focusing speed.Īn optometrist measures visual acuity with an instrument called phoropter in a procedure called a refraction. It is a poor indicator of a person’s ability to see colored objects, moving objects or depth perception- all qualities of one’s vision. This measurement is useful for a relative comparison of clarity of vision in a standard situation. Also the measurement is using high contract- black letters on white background. Why? Well, 20/20 vision is measured statically for one- in other words while the person is not moving.
Vision is a term that is too general to accurately describe what the 20/20 measurement denotes. While we tend to say “20/20 vision” a more proper term is 20/20 visual acuity. Why do you keep saying 20/20 visual acuity? If this is the smallest letter you can read WITH corrective lenses in front of your eyes, you are legally blind. The single “E” at the top of the chart represents 20/200 vision. If you can read the 20/10 line- your visual acuity is two times better than someone who can only read the 20/20 line. The smaller letters in lines below the 20/20 line correspond to better than 20/20 visual acuity. The letters get larger as the lines go toward the top of the chart and each line corresponds to worse visual acuity. If you can identify the letters on this line, but none of the smaller letters on lower lines, you have 20/20 vision. At this distance, one of the smaller lines at the bottom of the eye chart has been declared the standard- to correspond with normal visual acuity. In the Snellen measurement system- the top number represents the distance between the person and the eye chart. Could he even have dreamed that 158 years later optometrists all over the US would be doing a happy dance that the year 2020 is going to be their year. Herman Snellen, developed the 20/20 measurement system for visual acuity in 1862.
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