How to Measure Astigmatism: 7 Steps
Introduction:
Astigmatism is an eye condition that occurs when the cornea or lens has an irregular shape, leading to blurred or distorted vision. Accurate measurement of astigmatism is essential for proper diagnosis and treatment. Here are seven steps to measure astigmatism.
Step 1: Consult an Eye Care Professional
Always consult an eye care professional, such as an optometrist or ophthalmologist, for a comprehensive eye examination. They have the necessary equipment and expertise to accurately measure astigmatism.
Step 2: Visual Acuity Test
A standard visual acuity test, such as reading letters on the Snellen chart from a distance, helps determine the clarity of your vision. The test results can indicate if astigmatism might be present.
Step 3: Keratometry
Keratometry is a diagnostic procedure that measures the curvature of the cornea. It involves using a keratometer to shine light onto the cornea and measure its reflection to determine its shape. This test helps identify astigmatism caused by a misshapen cornea.
Step 4: Refraction Test
A refraction test calculates the prescription needed for corrective lenses by gauging how light passes through the eye. During this test, you’ll look through a device called a phoropter while the eye care professional changes lenses to determine which combination provides the sharpest focus.
Step 5: Manual Measurement with Javal-Schiotz Ophthalmometer
Some eye care professionals may use a Javal-Schiotz Ophthalmometer for manual measurement of astigmatism. This device assesses the curvature of both cornea and lens, providing valuable information about irregularities that may cause astigmatism.
Step 6: Corneal Topography
Corneal topography is an advanced technique used to create a detailed map of your cornea’s surface. It employs a specialized device to project a series of concentric rings on the corneal surface and captures their reflections using a camera. This test provides additional information about corneal irregularities related to astigmatism.
Step 7: Review Results and Discuss Options
After completing the necessary tests, your eye care professional will discuss the results and recommend any required treatments, such as eyeglasses, contact lenses or, in some cases, laser eye surgery.
Conclusion:
Measuring astigmatism is crucial for diagnosing and addressing vision issues. By following these seven steps under the guidance of an eye care professional, you can ensure proper measurement and treatment of astigmatism to maintain optimal vision.