Laser eye surgery, encompassing procedures like LASIK, PRK, and SMILE, has become a popular method for correcting common vision problems. Many individuals considering these procedures often wonder if the visual improvements achieved will truly last indefinitely. While the changes made to the eye are permanent, the body’s natural aging processes can still influence vision over time.
How Laser Eye Surgery Works
Laser eye surgery primarily functions by permanently reshaping the cornea, which is the clear, dome-shaped front surface of the eye. This reshaping alters how light enters the eye, allowing it to focus correctly on the retina and thereby improving vision. For instance, in LASIK, a thin, circular flap is created in the cornea, and an excimer laser then precisely removes microscopic pieces of tissue from the underlying corneal layer. After the reshaping, the flap is repositioned to act as a natural bandage, healing without the need for stitches.
These procedures effectively correct refractive errors such as nearsightedness (myopia), farsightedness (hyperopia), and astigmatism. Nearsightedness, where distant objects appear blurred, is corrected by flattening the cornea, which moves the light’s focal point backward onto the retina. Conversely, farsightedness, making close objects blurry, is addressed by steepening the cornea, bringing the focal point forward. Astigmatism, caused by an irregularly shaped cornea, is corrected by smoothing out these irregularities to ensure sharper vision.
Why Vision Can Change Over Time
Despite the permanent reshaping of the cornea by laser eye surgery, a person’s vision can still change years later due to natural, age-related processes that are distinct from the surgery’s effects. One common change is presbyopia, a condition that typically begins in the 40s. Presbyopia occurs because the eye’s natural lens, located behind the cornea, gradually hardens and loses its flexibility, making it difficult to focus on nearby objects. This is a universal aging phenomenon and is not caused or prevented by laser eye surgery, as the surgery only modifies the cornea.
Another age-related change that can affect vision is the development of cataracts. Cataracts involve the clouding of the eye’s natural lens, leading to blurred or impaired vision. While laser eye surgery does not cause cataracts, individuals who have had the procedure can still develop them as a natural part of aging, just like anyone else. Over half of people over 80 years old in the United States have cataracts or have undergone surgery to treat them.
In a small percentage of cases, minor regression of the initial correction can occur, often due to natural healing responses or subtle, ongoing changes in the eye. This is typically a slight shift in the refractive error and is less common than age-related conditions like presbyopia or cataracts. The progression of underlying refractive errors, such as nearsightedness, may also continue in some individuals.
Managing Post-Surgery Vision Changes
When vision changes occur years after laser eye surgery, several options are available to manage them. For minor regressions of the initial correction, an enhancement procedure, sometimes called a “touch-up,” may be considered. These procedures, such as LASIK enhancement or PRK, are designed to fine-tune the vision and address any residual refractive errors. An enhancement is performed after vision has stabilized.
Corrective eyewear, such as glasses or contact lenses, may become necessary, particularly for presbyopia. Individuals who have had laser eye surgery often find they require reading glasses as they enter their 40s to assist with near vision tasks. Some may opt for monovision, where one eye is corrected for distance and the other for near vision, to reduce the need for reading glasses.
If cataracts develop, they can be treated with standard cataract surgery, which involves replacing the cloudy natural lens with an artificial intraocular lens. Having undergone laser eye surgery does not prevent a person from having cataract surgery. It is important to inform the cataract surgeon about any previous laser eye surgery, as this information is relevant for calculating the power of the new lens implant. Regular comprehensive eye exams are also important to monitor overall eye health and detect any changes early.