When light passes through the eye, it can be distorted by imperfections found in the cornea and the lens of the eye. This distortion of light is known as a visual aberration. The vast majority of visual aberrations create common refractive errors like nearsightedness, farsightedness, and astigmatism, all of which can be treated with prescription eyewear or traditional laser eye surgery methods. About 10 percent of the population suffers from higher order visual aberrations that are unique, much like a fingerprint. To treat higher order aberrations it is necessary to create a customized map of the eye.

What is an aberrometer?

Aberrometers are the diagnostic tools that are used to identify visual errors. Aberrometry is a new way of measuring visual error that allows physicians to differentiate between traditional refractive error and higher order visual aberrations. An aberrometer is different from corneal topography in that it measures the optical quality of the eye relative to both the cornea and the lens of the eye.

Reasons for aberrometer testing

An aberrometer measures the average optical quality of the eye and also takes it a step further by measuring the total refractive power of the eye. The aberrometer maps every variation of the eye from the cornea to the retina, detecting even obscure vision errors. This allows physicians to measure both the quantity and quality of vision and identify both lower and higher order aberrations.

Aberrometers are primarily used as part of a custom LASIK procedure. Physicians can completely customize laser eye treatment to your individual needs based on diagnostic information provided by the aberrometer. Many ophthalmologists are also incorporating aberrometers into their routine eye examinations as well to get the most accurate reading of their patient's visual errors.

Performing an aberrometer test

In order to identify refractive error, the aberrometer sends out a band of laser light into your eye. The light passes through the cornea and the lens of your eye and is reflected back by the retina. This reflected light is then measured by the aberrometer to identify lower and higher order aberrations. Finally, the aberrations are displayed in 3-D images on a computer screen.

The information from the aberrometer is interfaced with the laser used during laser vision correction surgery. The map created by the aberrometer directs the delivery of laser light that precisely reshapes the cornea.