Use a clock-dial style astigmatism test to check whether some line orientations look darker, sharper, or blurrier than others. Get a rough screening summary and practical follow-up guidance for home eye checks.
Use this clock-dial style astigmatism test to check whether some line orientations look darker, clearer, or blurrier than others. It is a rough home screen, not a prescription tool. Compare it with the Visual Acuity Test or the Eye Chart Simulator (Snellen).
Choose the eye, correction, and viewing distance you are using. Then look at the clock dial and mark the spokes that look darker or clearer than the rest.
If some lines look darker or clearer than others, tap those line orientations below the chart.
An astigmatism test looks for uneven sharpness across different line directions. A common home-style version uses a clock dial or fan chart. If some spokes look darker, thicker, or clearer than others, that can suggest a directional blur difference worth checking more formally.
This tool works as a rough screen only. It does not measure cylinder power or tell you a prescription axis. For more eye checks, browse the Eye Check & Assessment category.
The chart shows multiple spokes at different angles. You look at the dial and note whether one orientation stands out as darker, sharper, or blurrier. The tool then summarizes whether your selections looked uniform, mildly directional, or more strongly directional.
You can check both eyes together or compare one eye at a time with and without correction.
Keep your distance consistent and notice whether some spokes stand out more strongly than others.
If the lines look uniform, use the “all spokes look similar” option instead.
The tool describes whether the response looked even, directional, or mixed and suggests practical follow-up.
Example: if the 45° and 60° spokes look darker or clearer than the others while the rest of the dial looks lighter, the tool will describe that as a directional response. That does not confirm astigmatism on its own, but it is a practical reason to compare one eye at a time and consider a formal refraction if the pattern repeats.
If you also want to check distance clarity, compare this with the Visual Acuity Test or the Eye Chart Simulator (Snellen).
Lighting, reflections, and screen contrast can make one line direction seem stronger than it really is.
A phone, tablet, and monitor can all render the same chart with different sharpness and aliasing.
Tired or dry eyes can create inconsistent chart responses that look directional even without clear astigmatism.
Moving closer or farther from the chart changes how the lines look almost immediately.
Old glasses, poor lens alignment, or testing without your normal correction can all affect the response.
A real refraction measures lens power and axis. This chart only screens for uneven line clarity.
Use it for a rough Snellen-style clarity check alongside the astigmatism chart.
Helpful when you want a full chart display for distance-vision screening practice.
Compare uneven chart impressions with digital eye strain symptoms and habits.
Browse the full eye screening and assessment category.
No. It only screens whether some line directions stand out more than others on a simple clock-dial chart.
Not reliably. A home chart can suggest a directional difference, but it cannot measure a prescription axis accurately enough for glasses or contacts.
Yes, that is often more useful. Both-eyes testing can hide a difference if one eye is compensating for the other.
That is generally a reassuring screen result, but it does not rule out other refractive errors or eye problems.
Display sharpness, glare, contrast, and scaling all change the appearance of fine lines, which is why this remains a rough home tool only.
Astigmatism Test is part of the Eye Check & Assessment collection. If you want a broader view of similar workflows, open the Eye Check & Assessment category page or browse all QuickTools categories.
Common next steps after this tool include Visual Acuity Test, Eye Chart Simulator (Snellen) and Color Blindness Test.
Estimate a rough Snellen-style visual acuity result such as 20/20 or 20/40 from the smallest line you can read. Get decimal acuity, logMAR context, screening guidance, and practical next steps for a home-style vision check.
Display a responsive Snellen-style eye chart on screen with full-chart and single-line modes, scaling controls, mirrored view, contrast options, and distance presets for rough home-style vision screening practice.
Take a quick Ishihara-style color blindness test on screen using hidden-number dot plates. Get a rough color vision screening summary, answer pattern signals, and practical next steps for follow-up.
Check how small a line of text you can read comfortably at a near reading distance. Get a rough reading-card style near vision summary and practical next-step guidance for home screening.
Format, validate, minify, or sort JSON data with configurable indentation. Instantly check for syntax errors, view node count and nesting depth — free, no sign-up required.
Generate QR codes for URLs, text, Wi-Fi credentials, vCards, and more. Customise foreground and background colour, error correction level, margin, and download as SVG or PNG — free and instant.
Calculate your Body Mass Index, healthy weight range and ideal weight using metric or imperial units.
Estimate daily calorie needs based on age, gender, height, weight and activity level using Mifflin-St Jeor, Harris-Benedict or Katch-McArdle formulas.