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Writer's pictureMaria Cholakova

Free Online Eye Tests for Astigmatism at Home

Do you want to do an eye test at home before you visit the eye doctor? In this publication, we will share links to free online tests for astigmatism resources you can explore. Be aware, these tests are a practical first step if you’re curious about whether astigmatism might be impacting your vision but they are not a method of self-diagnose. Visiting an eye care specialist remains the gold standard for diagnosis and treatment.


Let’s walk through how you can check for astigmatism at home with a few clicks.


Signs You May Have Astigmatism


Astigmatism occurs when the cornea or lens of the eye has an irregular shape. The irregular curvature causes light to focus unevenly on the retina, leading to vision issues. Before self-testing yourself, you need to recognize some of the common symptoms of astigmatism:


  • Blurred or distorted vision

  • Eye strain or discomfort

  • Headaches after prolonged visual tasks

  • Difficulty seeing clearly at night

  • Squinting to see more clearly

astigmatism prescription example
The CYL number on a prescription indicates astigmatism and how pronounced it is.

How to Perform an Online Astigmatism Test?


1. Set Up Your Environment


  • Ensure you have a well-lit room

  • Sit approximately 14 inches (35 cm) from your screen

  • Remove any corrective lenses if you wear them unless the test specifies otherwise


2. Access a Reliable Astigmatism Chart


Look for online astigmatism tests that use a fan chart or radial line test. Most of these charts consist of multiple lines radiating from a central point, which can identify uneven vision.

Eye test called "Astigmatism clock"
The "Astigmatism Clock" chart is the most common diagnostic tool in ophthalmology and optometry to assess astigmatism.

The classic Astigmatism chart resembles a traditional clock face. It consists of 12 radial lines extending outward from a central point. The lines are labeled with numbers corresponding to the hours on a clock (e.g., 12, 3, 6, 9). These lines are equally spaced at 30-degree intervals.


3. Follow the Instructions


  • Cover one eye and focus on the chart with the other

  • Pay attention to whether some lines appear darker, bolder, or more blurred compared to others

  • Repeat the process with the other eye


4. Interpret the Results


When the cornea or lens has an irregular curvature (astigmatism), light entering the eye focuses unevenly. The lines perpendicular to the axis of the steepest curvature will appear clearer or darker because they align more closely with the astigmatic meridian. Conversely, lines along the flattest curvature axis may appear faint or blurred.


An online test cannot replace a comprehensive eye examination by a professional.


How the Astigmatism Clock Chart Works?


The chart identifies the orientation and severity of astigmatism by using the principle of contrast sensitivity.


In the doctor's office, the patient views the chart, often without corrective lenses, from a specified distance (e.g., 6 meters or 20 feet). The patient is asked to observe and report which set of lines appears darker, bolder, or sharper compared to others.


If certain lines look distinctly different, it may indicate astigmatism. The orientation of the clearest lines corresponds to the axis of astigmatism (e.g., if lines near "3 o'clock" are sharper, the astigmatic axis might be around 90 degrees).


The clock chart is primarily a screening tool and not a substitute for detailed examination. Results are used alongside objective methods like keratometry, corneal topography, or automated refraction.


Free Online Eye Tests for Astigmatism


OPTOPLUS Virtual Astigmatism Test


Stand about 3 feet from your screen, cover one eye, and observe the provided image. If some lines appear greyer than others, it may indicate astigmatism.



Prokerala Astigmatism Test


This online test uses images to help determine if you might have astigmatism. Maintain a distance of about 14 inches from your screen and follow the instructions provided.



Lentiamo Astigmatism Test


Position yourself approximately 35–40 cm from the screen, cover one eye, and observe the image. If certain lines appear blurry or unclear, it could suggest astigmatism.



ZEISS Online Vision Screening


Follow the on-screen instructions to evaluate various aspects of your vision. This online vision test includes an assessment for astigmatism.



astigmatism night vision

Pros & Cons of Online Eye Tests for Astigmatism


  • Convenience: Test your vision anytime, anywhere

  • Cost-Free: Most online tests are completely free

  • Quick Insights: Gain a preliminary understanding of your eye health

  • Lack of Precision: They cannot measure the exact degree of astigmatism

  • No Prescription: Online tests won’t provide prescriptions for corrective lenses

  • Not a Substitute for Medical Care: Only a licensed eye doctor can offer a complete diagnosis and set up an adequate treatment plan


When to See an Eye Doctor?


If an online test suggests astigmatism, or if you experience persistent vision problems, schedule an appointment with an ophthalmologist or optometrist. Early management can prevent further complications and enhance your quality of life.



Conclusion


Online eye tests for astigmatism are a convenient way to take the first step in understanding your vision. While these tests are not a replacement for professional care, they can help you identify potential issues and prompt you to seek further evaluation. Take a moment today to test your eyes and prioritize your visual health.


Medically reviewed

Checked by Atanas Bogoev, MD.

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