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📚 User Guide
What it Detects

Metamorphopsia — straight lines appear wavy or bent (early AMD, macular edema, epiretinal membrane)

Central scotoma — a blurry or missing area near the center (macular hole, geographic atrophy)

Asymmetry — one eye sees something the other does not (often unilateral disease)

Setup

• Reading glasses ON (if you use them for near work)

• 30 cm viewing distance — measure from eye to screen

• Normal indoor lighting (avoid glare or dim rooms)

• Screen PPI calibration (96 / 110 / 144 are common)

• Cover one eye; never test both simultaneously

When to Seek Care

• Sudden new distortion or missing area — same-day evaluation

• Known AMD / diabetic retinopathy: daily self-check

• Stable abnormality with vision change — within 1 week

• Result is a screen, not a diagnosis — confirm with an ophthalmologist

Related Guides
⚠️ 本工具仅供辅助参考，不构成医疗诊断或治疗建议。如有视力问题，请及时就诊专业眼科医生。
📋 Standard Test Procedure (AAO Clinical Guidelines)
  1. Wear your usual reading glasses (presbyopia correction).
  2. Hold the device 30 cm from your eyes (about arm's length).
  3. Use normal indoor lighting (avoid glare or a dim room).
  4. Cover one eye — test the right eye first, then the left.
  5. Stare at the central white dot; be aware of the grid in your peripheral vision.
  6. Tap any cell where you notice lines bending, blurring, dark, or missing.
  7. Compare both eyes — if one eye sees something the other does not, that is abnormal.
📏 Screen calibration (optional — recommended on first use)

We use it to report the real physical size of each cell. Don't know your PPI? Common values: 96 (Windows) · 110 (Mac) · 144 (high-DPI laptops). Defaulting to .

Tested eye:
20 × 20 standard grid · 148 mm square · 28° field at 30 cm ·tap any cell to mark an abnormality
📝 Test Notes
⚠️ Clinical warning:
  • The Amsler Grid is a screening tool, not a diagnostic one. Any abnormality must be confirmed by a professional eye exam.
  • Sudden line distortion (metamorphopsia) or central scotoma may signal macular edema, AMD, or central serous chorioretinopathy.
  • A difference between the two eyes (one normal, one abnormal) usually indicates unilateral disease and needs prompt evaluation.
  • Patients with known AMD, diabetic retinopathy, or high myopia should perform daily self-checks.

📚 Clinical Sources

All calculations follow peer-reviewed, published formulas. The list below cites the primary literature for each model.

  1. Amsler M. Le champ visuel scotopic. Bulletin de la Société Française d'Ophtalmologie, 1954;67:5-10.
  2. AAO Preferred Practice Pattern — Age-Related Macular Degeneration. American Academy of Ophthalmology, 2022.
  3. International Myopia Institute (IMI) 2021 — Macular Function Report.
  4. Zhao Kanxing. Clinical Ophthalmology. People's Medical Publishing House, 2017.
💡

⚠️ Medical Disclaimer

This tool is for educational and clinical reference only, and does NOT constitute medical advice, diagnosis, or treatment. No doctor–patient relationship is created by using this tool. Always consult a licensed ophthalmologist for clinical decisions.

Questions or corrections? Email eyetoolkit@foxmail.com