How Lower and Higher Order Aberrations Affect Your Vision
By Andrew E Holzman, MD FACS on January 11, 2012
At TLC Tysons Corner, I am proud to offer the most advanced and effective laser vision correction technology to our Virginia LASIK patients. I employ use of custom wavefront LASIK systems, which identify and treat your unique refractive irregularities, including the higher order aberrations that affect the quality of your vision. Higher order aberrations cause vision problems such as glare, double vision, and difficulty seeing in low light conditions. Prior to the development of wavefront LASIK technology, surgeons were unable to detect and treat these vision errors. Read on to learn more about lower and higher order aberrations.
Lower Order Aberrations
Lower order aberrations refer to some well-known vision errors: nearsightedness, farsightedness, and astigmatism. These conditions are related to the shape, or curvature, of the cornea. If the cornea is irregularly shaped, light does not properly reflect off of the retina. This results in blurry vision at near and/or far distances.
Treatment for Lower Order Aberrations
There are many treatment options for lower order aberrations; each treatment is associated with its own advantages and disadvantages.
- Eyeglasses: Eyeglasses are the most common treatment for refractive errors. They are typically the least expensive solution, but many patients do not like the way that they look when wearing glasses.
- Contact lenses: Contact lenses allow patients to see clearly without glasses, but many patients complain that they are uncomfortable or inconvenient.
- Laser vision correction surgery: Laser vision correction surgery such as LASIK and PRK permanently reshape the cornea to correct the refractive errors that cause blurry vision. However, some patients are deterred by the cost of laser vision correction surgery. Financing plans can make LASIK more affordable for patients that are concerned about the price of treatment.
While lower order aberrations account for 85 percent of refractive irregularities of the eye, higher order aberrations account for remaining 15 percent. Higher order aberrations refer to the more complex refractive irregularities that affect visual acuity.
Higher Order Aberrations
A wavefront of light will pass through a perfect eye in a flat plane. When it passes through one with irregularities in the cornea, crystalline lens, tear film, aqueous humor, and vitreous humor, it produces distorted, three-dimensional shapes. These deviated shapes are known as higher order aberrations. Presently, experts have identified more than 60 higher order aberrations, including comas, spherical aberrations, and trefoils. These imperfections worsen a person's quality of vision and result in the following vision problems:
- Double vision
- Ghost vision
- Starburst patterns
- Loss of contrast
- Difficulty seeing at night
Treatment for Higher Order Aberrations
The development of wavefront technology and custom LASIK systems marked a major advancement in the detection and treatment of higher order aberrations. Wavefront technology maps higher order aberrations in the eyes by measuring the difference between the patient's wavefront shape and the ideal flat plane that represents the perfect eye. The computerized wavefront map is then used to guide the excimer laser as the cornea is reshaped during the custom LASIK procedure. Because both lower and higher order aberrations are corrected with custom LASIK surgery, patients enjoy crisper, more focused vision than can be achieved with eyeglasses, contact lenses, and traditional LASIK surgery.
Contact TLC Tysons Corner today to schedule your LASIK consultation at my practice.