Peripheral Vision in LASIK and PRK Laser Eye Surgery

Laser vision correction eye surgery — and contact lens wear — typically do not limit peripheral vision. Glasses, by contrast, do tend to limit peripheral vision in proportion to the power of the prescription.

A patient from Santa Barbara recently told me that he loved his peripheral vision with his contact lenses, but felt he lost his peripheral vision when he wore his glasses. I was able to reassure him that after LASIK, his peripheral vision typically should be much more similar to his contact lens vision than to his glasses vision.

The reason that LASIK and contact lenses both typically do not affect or limit peripheral vision is that they both sit directly on the cornea itself — the front layer of the eye. Glasses, by contrast, sit off the eye and produce several distortions simply because they sit away from the eye. Think of the difference between holding a magnifying lens close to your eye and then moving it away. Clearly distance causes optical changes.

Glasses tend to limit peripheral vision since, of course, there is no correction off to the side of your vision. In addition, glasses require you to look through their optical centers — the “sweet spot” in the lens. If you look away from this center point, the lens produces distortion. Therefore, if you are looking straight ahead, your peripheral vision to the side of this straight ahead point is looking through this distortion. So, depending on how far peripheral to center you are considering, glasses either distort peripheral vision or simply do not provide any peripheral correction at all.

Glasses also tend to change image size. Nearsighted glasses minimize the image and farsighted glasses magnify the image — both at a rate of approximately 2 percent per diopter of correction.

For these reasons, the optical downsides of glasses when compared to either contact lenses or successful LASIK, are greater the higher the degree of prescription.

Many patients who are considering LASIK only wear contact lenses and never wear their glasses simply because they do not like the quality of glasses vision. Unfortunately, it is necessary to leave the contact lenses off long enough for the cornea to resume its normal shape as contact lenses mold the cornea. While many of my patients truly dislike having to wear glasses while the cornea “gets a breather” and recovers its true shape before LASIK, this is a step that is well worthwhile to allow us to get the most accurate measurements of the cornea in order to give the best possible LASIK results.

See Also

Peripheral Vision and LASIK
A research paper concludes LASIK can influence peripheral vision.

Glasses Cause Distortion and Poor Peripheral Vision
An optician from the U.K. discusses some of the optical downsides of glasses, including regarding peripheral vision.

Aspheric Eyeglass Lenses for Better Vision and Appearance
All About Vision discussion on how newer glasses technology can help minimize some of the inherent optical downsides of wearing glasses.

Contact Lenses versus Eye Glasses: Which Are Best for You?
All About Vision discussion of the pros and cons of contacts compared to glasses.

LASIK: What Are the Risks
The FDA discussion of the risks of LASIK.

LASIK Results: What to Expect
All About Vision discussion of what to expect after LASIK laser eye surgery.

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