Online Vision Test 2
Online Vision Test is a measurement created by Pott Glasses to find out the closest power by checking the VA at 1m. This test however is not 100% accurate and comes with limitations and assumptions.
Limitations:
- Hard to predict hyperopic refractive error
- Hard to predict if the power increase or decrease
- Uncorrected astigmatism might affect the VA
- Not accurate in those who have low sph high astig
- Accommodation take place at 1m
- The higher the power, larger the dioptric error. The accuracy of diopter estimation is reduced for VA worse than or equal to 6/60
Assumptions:
- Subjects are myopes without astigmatism, accommodation is not exerted during the test
- All subjects best corrected VA is 6/6. If aided VA cannot reach 6/6, assume short-sighted power is increase rather than decrease
- The higher the power, larger the dioptric error. The accuracy of diopter estimation is reduced for VA worse than or equal to 6/60
Due to these limitations and assumptions, this Online Vision Test is suitable for people with
- power less than -3.00
- astigmatism less than -1.00
- non glasses wearer who find vision blurry
If you meet the criteria, then you may proceed with the test.
Here are the steps.
- Take out your IC or driving license or credit card and place it over the red box. Adjust the size of the red box by zooming in or out to make sure that it fits the card nicely. (this is crucial step as we need to calibrate the size)
- Be seated at the same level with your computer screen. Position yourself 1 meter to the computer screen. Make sure the chart is same level with your eyes.
- To measure unaided VA (visual acuity without correction), remove your glasses or contact lenses during the test. Test one eye at a time.
- Start with the right eye. Cover your left eye with your palm without pressing on it, record the smallest row of letters that you able to see. Write down the number of the smallest line with more than half of the letters that you identified correctly.
- Repeat the test with the other eye covered and record the results. To make the examination easier and faster, get a person to help you by showing the letters among the lines of letters
Once you’ve completed the test, fill in the result and details in the following column. We will contact you to double check the result before proceeding with your prescription glasses order.