Farsightedness, also known as hyperopia, is a common vision condition. It causes blurred vision, especially when viewing objects up close, and can lead to eye strain or headaches. LASIK (Laser-Assisted In Situ Keratomileusis) is a surgical option to correct refractive errors, including farsightedness. This procedure reshapes the eye’s cornea to improve how light is focused, potentially reducing or eliminating the need for corrective lenses.
What is Farsightedness?
Farsightedness, or hyperopia, is a refractive error where the eye does not bend light properly, causing nearby objects to appear blurry. This occurs because light entering the eye focuses behind the retina, instead of directly on it. People with mild farsightedness might not notice symptoms, especially when younger, due to the eye’s natural ability to accommodate.
Farsightedness typically involves an eyeball that is shorter than average from front to back, or a cornea that is too flat. Both conditions prevent light rays from converging precisely on the retina. While often present from birth, its effects can become more noticeable with age as the eye’s natural focusing ability diminishes.
How LASIK Addresses Farsightedness
LASIK surgery works by precisely reshaping the cornea to alter how light enters and focuses on the retina. For farsightedness, the excimer laser is used to make the central cornea steeper. This increased curvature helps to redirect light rays so they converge directly on the retina, correcting the blurred vision.
This approach contrasts with how LASIK corrects nearsightedness, where the laser flattens the central cornea to reduce its curvature. By adding curvature for farsightedness, LASIK effectively compensates for an eyeball that is too short or a cornea that is too flat, allowing for clearer vision.
The Success and Limitations of LASIK for Farsightedness
LASIK can be a highly effective treatment for farsightedness, with many patients experiencing significant vision improvements and reduced dependence on glasses or contact lenses. Studies indicate that for mild to moderate farsightedness, ranging from +1.00 to +6.5 diopters, LASIK has a high success rate, with many achieving 20/25 vision or better without correction. Most LASIK patients (around 99%) achieve 20/40 vision or better, the legal standard for driving without corrective lenses.
Despite its effectiveness, LASIK for farsightedness does have limitations. The maximum degree of hyperopia that can be effectively corrected ranges from +4.00 to +6.00 diopters, though some surgeons may treat up to +6.00 diopters. Beyond this range, the predictability of outcomes and long-term stability may decrease, and the risk of needing enhancement procedures can increase. LASIK also does not prevent presbyopia, the age-related loss of near vision that begins around age 40. Individuals who undergo LASIK for distance vision may still require reading glasses later in life.
Who is a Candidate for LASIK for Farsightedness?
Determining candidacy for LASIK for farsightedness involves several factors to ensure a safe and effective outcome. Patients should be at least 18 years old, with many ophthalmologists recommending waiting until at least the mid-20s, as vision tends to stabilize during this period. A stable prescription, with no significant changes for at least one to two years, is also important.
Overall eye health is also considered, including adequate corneal thickness for reshaping without compromising structural integrity. Conditions such as severe dry eye, keratoconus (a progressive thinning of the cornea), or certain autoimmune diseases may disqualify a candidate. An eye surgeon will conduct a comprehensive evaluation, including corneal mapping, to assess suitability and discuss realistic expectations regarding the procedure’s outcomes.