LASIK can treat farsightedness (hyperopia), but the procedure is often more complex and has stricter eligibility limits than when treating nearsightedness (myopia). Hyperopia occurs when the eye is too short or the cornea is too flat, causing light to focus behind the retina instead of directly on it. This results in blurred vision, particularly for near objects. Treating hyperopia with LASIK requires a precise balance between the patient’s prescription and the health of their corneal tissue.
How LASIK Corrects Farsighted Vision
LASIK corrects farsightedness by changing the curvature of the cornea to increase its focusing power. An excimer laser precisely reshapes the tissue beneath a thin, hinged flap created on the cornea’s surface. For hyperopia, the goal is to make the central cornea steeper, which is the opposite of the process used for nearsightedness.
To achieve this steepening effect, the laser removes more tissue from the cornea’s periphery than from its center. This removal effectively pulls the center forward, making the central surface more curved. This steeper profile allows light rays to bend more sharply, shifting the focal point onto the retina. Hyperopic correction requires a wider ablation zone, which can impact the cornea’s overall shape and stability more than myopic correction.
Who Is a Candidate for Hyperopic LASIK
Candidacy for hyperopic LASIK is determined by a thorough examination assessing several clinical factors. The stability of the patient’s prescription is paramount; candidates must have had a stable prescription for at least one year. Hyperopia often changes with age, especially as presbyopia (age-related loss of near focusing ability) begins. Stable vision is therefore a foundational requirement for the procedure.
Prescription limits for hyperopic LASIK are generally stricter than those for myopia. Most surgeons cautiously treat hyperopia in the range of +0.75 to +4.00 diopters. Some advanced platforms may treat up to +5.00 or +6.00 diopters in carefully selected cases. Treating prescriptions higher than +4.00 diopters carries an increased risk of regression, where the eye gradually reverts toward its original state.
Corneal thickness is a critical factor because hyperopic correction requires peripheral tissue removal, affecting structural integrity. Surgeons must ensure enough tissue remains beneath the flap to maintain corneal strength and prevent complications. The size of the patient’s pupils also influences eligibility, as a large pupil combined with a wide ablation zone may increase the risk of glare or halos in low-light conditions. Overall eye health, including the absence of severe dry eye syndrome or other corneal diseases, is also factored into the final decision.
Surgical Alternatives to LASIK
Patients ineligible for LASIK due to a high prescription, thin corneas, or age-related changes have other effective surgical options. Photorefractive Keratectomy (PRK) is often recommended for patients whose corneas are too thin for the LASIK flap. PRK is a surface ablation technique that reshapes the cornea without creating a permanent flap, making it a viable option for corneal stability concerns.
While PRK offers similar long-term results to LASIK, the initial recovery time is longer because the epithelium must regrow over several days. For older patients, particularly those over 40 or 45 with higher hyperopia, Refractive Lens Exchange (RLE) may be preferred. RLE is identical to cataract surgery, where the eye’s natural lens is removed and replaced with an artificial intraocular lens (IOL).
RLE is highly effective for severe hyperopia and eliminates the future need for cataract surgery, as the artificial lens cannot develop a cataract. Modern IOLs used in RLE can also correct for presbyopia, offering a solution for both distance and near vision. This makes RLE a comprehensive solution for hyperopic patients experiencing age-related vision changes.