The latest articles on DEV Community by 王忠明 (@_1d83187776d42a2f1bee6). https://dev.to/_1d83187776d42a2f1bee6 https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3708300%2F80385ab0-3f52-47bd-8484-dcd2cfac0301.png https://dev.to/_1d83187776d42a2f1bee6 en 王忠明 Fri, 17 Jul 2026 05:35:37 +0000 https://dev.to/_1d83187776d42a2f1bee6/i-built-a-free-online-astigmatism-test-heres-how-it-works-21kc https://dev.to/_1d83187776d42a2f1bee6/i-built-a-free-online-astigmatism-test-heres-how-it-works-21kc <p>Astigmatism affects roughly 1 in 3 adults, but most people don't know they have it. An optometrist can diagnose it in minutes, but getting to one isn't always convenient.</p> <p>Enter the Siemens Star — a radial pattern of black and white lines. If all lines look equally sharp, your vision is likely fine. If some lines appear grey or blurry while others stay crisp, that's a strong sign of astigmatism.</p> <p>I came across this concept a while ago and realized something: most Siemens Star images online are terrible. Low resolution, badly printed, hard to use. So I built a free interactive version.</p> <p>sighthealthpro.com — 30 seconds, no signup, works in your browser.</p> <p>The tool is not a diagnosis. It's a screening layer that helps you decide whether to book an actual eye exam. If the test flags anything unusual, the next step is always an optometrist with a phoropter.</p> <p>It's a simple tool, but sometimes simple tools solve real problems.</p> science showdev sideprojects webdev