Diagnosis of Astigmatism
Astigmatism is usually detected during a routine eye exam by an optometrist or ophthalmologist. The diagnosis of astigmatism involves several tests that assess vision clarity and eye shape.
1. Visual Acuity Test
- Measures how well you can see letters or symbols at various distances
- Uses a Snellen chart (the familiar letter chart)
2. Keratometry
- Measures the curvature of the cornea
- A keratometer shines light on the cornea and evaluates its reflection
- Helps identify the degree and axis of astigmatism
3. Corneal Topography
- Creates a detailed map of the cornea’s surface
- Detects irregular astigmatism and conditions like keratoconus
4. Refraction Test
- Determines the exact lens prescription needed to correct vision
- Uses a phoropter (the instrument you look through during eye exams)
5. Autorefractor or Aberrometer
- Automated tools that quickly measure how light passes through the eye
- Often used for screening or to support manual refraction results
Astigmatism can occur in children and may affect learning and reading. In South Africa, school vision screenings are becoming more common, but early detection still relies heavily on parental observation and regular optometrist visits.
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Diagnosis of Cataracts in Adults
Causes and Types of Astigmatism
