An autorefractometer (also called an auto-refractor) is a computerized machine used to measure the refractive error of the eyes — that is, it helps determine whether a person is nearsighted (myopic), farsighted (hyperopic), or has astigmatism.
Here’s how it works and what it does
🔍 How It Works
The patient looks into the device at an image (like a balloon, house, or small picture).
The machine automatically shines a light into the eye.
It measures how the light changes as it reflects off the retina at the back of the eye.
Using that data, it calculates an approximate prescription for glasses or contact lenses.
⚙️ What It Measures
Sphere (SPH): Nearsightedness or farsightedness
Cylinder (CYL): Astigmatism (irregular corneal shape)
Axis: The orientation of astigmatism