Hyperopia, commonly known as farsightedness, is a refractive error that causes individuals to have difficulty seeing close objects clearly, while distant objects often remain in focus. This vision impairment occurs when the eye does not bend light properly, causing light rays to focus behind the retina instead of directly on it. Hyperopic LASIK is a widely performed laser eye surgery that addresses this condition by reshaping the cornea, aiming to improve how light enters the eye and focuses on the retina. This surgical option can significantly reduce or even eliminate the need for corrective lenses for many individuals.
Understanding Hyperopia and How LASIK Corrects It
Hyperopia arises from an eyeball that is too short from front to back, or a cornea that is too flat. In a normally functioning eye, the cornea and lens work together to refract light precisely onto the retina, which then converts light into signals for the brain to interpret as images. When the light focuses behind the retina due to the eye’s shape, near objects appear blurry.
Hyperopic LASIK corrects this by reshaping the cornea to increase its curvature. During the procedure, a thin flap is created on the corneal surface, which is then lifted. An excimer laser then precisely removes tissue from the mid-periphery of the underlying corneal stroma. This targeted removal steepens the central cornea, allowing light to converge and focus correctly onto the retina, improving visual clarity. This process contrasts with myopic LASIK, which flattens the cornea to correct nearsightedness.
Who is a Candidate for Hyperopic LASIK?
Determining suitability for hyperopic LASIK involves a comprehensive eye examination and adherence to specific criteria. Candidates should be at least 18 years old, with many ophthalmologists recommending waiting until the mid-20s for vision to stabilize. A stable prescription, meaning no significant changes for at least one to two consecutive years, is important.
Corneal health and thickness are assessed, as the procedure involves reshaping this tissue. The cornea must be thick enough for the procedure. Overall eye health is considered, including no active eye diseases, infections, or conditions like keratoconus (a progressive thinning of the cornea). Hyperopic LASIK is effective for mild to moderate hyperopia, up to +4.00 to +6.00 diopters, though optimal results are seen with corrections up to +4.50 diopters.
The Hyperopic LASIK Procedure
The hyperopic LASIK procedure begins with pre-operative preparation. Anesthetic eye drops are applied to numb the eye, minimizing sensation during the surgery. A lid speculum is then used to hold the eyelids open, preventing blinking.
The next step involves creating a thin, hinged corneal flap. This can be achieved using either a mechanical device called a microkeratome or a femtosecond laser, which creates the flap with laser pulses. Once the flap is created, the surgeon lifts and folds it back, exposing the underlying corneal tissue, known as the stromal layer.
With the stromal layer exposed, an excimer laser is used to reshape the cornea. For hyperopia, the laser removes tissue from the mid-periphery of the cornea, which causes the central cornea to steepen. The patient is instructed to focus on a target light during this laser application, which lasts less than a minute per eye. After the reshaping is complete, the corneal flap is repositioned back over the treated area, where it naturally adheres.
Recovery, Results, and Potential Considerations
Immediately following hyperopic LASIK, patients may experience common sensations, including blurry or hazy vision, mild discomfort, or a gritty feeling in the eyes. Vision improves noticeably within the first 24 hours, though some fluctuations in clarity can occur during the initial days. Patients are advised to wear protective eye shields and to use prescribed eye drops to prevent infection, inflammation, and manage dry eye symptoms.
Vision stabilizes within the first few weeks, with most discomfort subsiding. While many patients achieve 20/40 vision or better without corrective lenses, and some reach 20/20, full stabilization can take three to six months. During this period, some individuals might notice temporary dry eyes, glare, or halos around lights. These visual disturbances diminish as the eyes continue to heal. Rarely, undercorrection or overcorrection may occur, which can be addressed with a follow-up procedure if vision remains unstable after several months.