Online eye test: Check your eyesight for free now
Medically reviewed by Ing. Petra Průchová, Optometrist, on 29 Jan 2021. Written by Lentiamo
The World Health Organization revealed new figures for vision impairment in October 2018. Globally, it is estimated that approximately 1.3 billion people live with some form of vision impairment. Regarding distance vision, 188 million people have mild vision impairment, 217 million have moderate to severe vision impairment, and 36 million people are blind. (World Health Organization)
All these people need some kind of visual aid, typically contact lenses or glasses, to improve their vision. But how do you find out if you need such visual aids? How do you measure your eyesight?
Monoyer's Eye Chart
In order to test your eyesight, you need to take an eye test.
The inventor of the first decimal eye test was Ferdinand Monoyer. The French ophthalmologist created his famous Monoyer Eye Chart in 1872 and provided a unit of measurement for the optical power of a lens, called a dioptre. Each row of letters in different sizes represents a different dioptre – the unit that is still in use today.
A dioptre is a unit of measurement of the optical power of a lens or curved mirror, which is equal to the reciprocal of the focal length measured in metres (that is, 1/metres). It is thus a unit of reciprocal length. For example, a 3-dioptre lens brings parallel rays of light to focus at 1⁄3 metre. Optical power of the human eye is 58 D.
Fun fact: Monoyer also inserted his name into the chart. Reading upwards, ignoring the last line, the letters on the left-hand side spell ‘Monoyer’, the letters on the right-hand side ‘Ferdinand’. Can you spot it? (Independent)
What about the Snellen Eye Chart?
Soon after Monoyer published his eye test, the Dutch eye doctor Herman Snellen developed a similar chart, the Snellen Eye Chart. The first version used abstract symbols, which were then replaced with letters. Unlike the previous model, it placed the largest letters at the top.
The chart consists of 11 lines of block letters, beginning with big letters on the top row. The size of the letters progressively decreases, allowing for more letters on each subsequent line. (Very Well Health)
The Snellen Chart is still used today to measure people’s eyes. During an eye exam the eye doctor will ask you to find the smallest line of text letters that you can make out, and ask you to read it. If you can read the bottom row of letters, your visual acuity is very good.
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Take an eye test here
If you want to find out whether you need glasses or contact lenses, book an eye test with your local eye care practitioner. Before you visit your doctor or optician, you can do the Snellen Eye Test at home.
The test we're providing here can be useful to test nearsightedness, which causes blurry distance vision. That is particularly helpful to screen children for nearsightedness.
Farsightedness, astigmatism, or other eye problems can't be measured with our chart. Only a comprehensive eye examination by a licensed eye specialist or ophthalmologist can determine whether your eyes are healthy and you can see as clearly and comfortably as possible.
How to use our online Snellen Eye Chart
For the best accuracy, have someone assist you when testing your vision with the Snellen Eye Chart.
- Place the chart on a wall about six metres away.
- Cover one eye and read aloud the letters on the chart.
- Begin at the top and move toward the bottom.
- Repeat with the other eye, and then with both eyes together.
- The smallest row of letters that you read accurately determines visual acuity in the uncovered eye.
How to interpret your results
The results of your chart reading will determine the quality of your eyesight. Your vision results will be expressed as a fraction. Fractions are shown to the left of each row and identify how well you can see. If you could read clearly to the fifth line, for example, your vision will be expressed as 20/40 vision. If you could read clearly to the seventh line, your vision will be expressed as 20/25. The numbers are given in feet, an American unit of measurement. One foot is about 30 cm.
20/20 vision: you see the same line of letters at 20 feet / 6.09 metres that people with normal vision see at 20 feet / 6.09 metres— this means your vision is perfect.
20/40 vision: you see the same line of letters at 20 feet / 6.09 metres that people with normal vision sees at 40 feet / 12.2 metres.
Comments
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Reply
Hii, i have been using specs since i was 10 yrs old and now i am 20, i have Farsightedness, my specs number kept on increasing. But from the last few months or almost a year, i have noticed something that when i do an eye exercise and when i stretch my eye and try to focus on the object which is kept at a distance becomes clear. And after that i put off my glasses and tried one another time, the result was same.
Can i recover my eyesight?-
ReplyHello,
Engaging in eye exercises can be highly beneficial for maintaining eye health and may contribute to stopping the progression of diopters or even improving your vision.
Nevertheless, I would strongly advise consulting with a doctor who can provide you with a more accurate prognosis.
Best regards,
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Reply
I use computer for hours in a day. First time, when I checked in a hospital they said that my eye power is -0.5. After a week, In another hospital I checked, they informed that my eye power for both eyes are -0.75. Finally, I went to another optometrist and they said -1 in left eye and -0.75 in right eye. So, I brought eye glasses of -1 and -0.75. But, sometimes I feel head ache and eye pain. Now at home, I tested my own and found more than -1 in both eyes (both eye different).
Will the eye get normal vision after wearing glasses? Will refractive error progress in a week? Is it necessary to use glasses all the time?-
Reply
Dear Krishna,
Thank you for your comment.
While it is possible that the dioptres do increase over time (and age), changes usually do not occur over a week.
The glasses will correct the vision whilst wearing them.
We'd suggest contacting your ophthalmologist to discuss how you should be wearing your glasses.
Regards.
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Reply
New glasses today. 20/20 each eye, and slightly better with both. Without glasses 20/100 Right eye, 20/80 left eye. Glasses seem quite strong, but have kept them on for seven hours .
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Reply
Dear Dale,
Thank you for your comment.
In order for the body and brain to get used to the new prescription glasses, it is recommended to wear them for at least 3 days to evaluate their use.
If you experience any discomfort, please contact your eye specialist.
Have a lovely day.-
Reply
Yes, the doctor said to wear them full time, for distance, and reading.
They are comfortable, but I have found that I need to push back reading material farther away from my eyes. Also everything appears much smaller, and incredibly clear than without glasses.
The prescription is, right eye - 1.75, and left eye -1.50.
The doctor said that I will probably need stronger lenses within a year, after my eyes get used to these. He said that this is a fairly strong first prescription.
My distance vision began to get quite blurred after I began working on a desktop for several hours a day.
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Reply
The vision of my right eye is 20/20 but that of my left eye is 20/32 , is it ok if i donot wear glasses?
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Reply
Hello,
Thank you for your comment.
It depends on your personal feeling, as long as you do not feel any discomfort when looking, it is not necessary to wear glasses.
If you would like to be sure that everything is fine, we recommend that you visit an eye specialist who will provide you with professional care.
Have a lovely day.
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