Scleral lenses are a specialized form of contact lens designed with a larger diameter, allowing them to rest gently on the white part of the eye, known as the sclera. This unique design creates a fluid-filled vault over the sensitive corneal surface, which is particularly beneficial for individuals with irregular corneal shapes, such as those caused by keratoconus, or for managing severe dry eye conditions. Understanding their long-term durability and required maintenance is fundamental for current and prospective wearers. Determining how long this specialized product will perform optimally involves distinguishing between the physical endurance of the material and the practical replacement cycle dictated by physiological changes.
Expected Overall Lifespan
The physical material of a scleral lens, typically a highly durable rigid gas-permeable (RGP) polymer, is designed to be sturdy and can last for several years. With excellent care, the material often maintains its structural integrity and clarity for two to three years, sometimes longer. Unlike soft lenses that are physically degraded by daily wear, the RGP material resists significant breakdown.
The actual lifespan for a patient, however, is generally between one and three years. The need for replacement is driven by changes in the eye rather than the lens breaking or physical failure. Conditions like keratoconus or post-surgical corneas can continue to change shape, altering the necessary vaulting and fit of the lens over time.
Changes in the corneal contour or the progression of an underlying eye disease necessitate a new lens design to maintain proper clearance. If the eye’s shape changes, the lens fit may become compromised, leading to discomfort or an increased risk of corneal irritation. A change in the patient’s underlying prescription can also prompt the need for a new lens, even if the current one is physically pristine.
Microscopic scratches or persistent surface deposits that cannot be removed through routine cleaning can also degrade the quality of vision and comfort. Daily handling and cleaning can eventually lead to minute damage that compromises the optical surface. Regular, comprehensive eye examinations, typically performed annually, are necessary to monitor the lens fit and the underlying health of the eye.
Daily Wear Limits and Comfort
While a scleral lens can last for years, its daily wear is limited by the eye’s physiology and the lens design, typically ranging from 12 to 16 hours. These lenses are made from gas-permeable materials, which allow oxygen to pass through to the cornea. The specific maximum wear time is determined by an eye care professional based on the individual’s corneal health and the lens’s oxygen transmissibility.
The fluid reservoir between the lens and the cornea, which provides continuous hydration, can also be a limiting factor. Over many hours, the saline solution can accumulate metabolic byproducts and cellular debris, leading to mid-day fogging or reduced clarity. This haziness is a common sign that the fluid needs to be refreshed, often requiring the lens to be removed, cleaned, and reinserted with fresh, sterile saline.
Extended daily wear beyond the recommended limit can lead to discomfort, increased eye redness, or dryness. These signs indicate that the ocular surface is experiencing stress and requires a rest period without the lens. Daily removal is also necessary to allow the eye’s surface to recover and to facilitate the thorough cleaning and disinfection process.
Essential Maintenance for Maximum Longevity
Achieving the maximum potential lifespan of a scleral lens depends heavily on a strict and precise daily care regimen. Proper handling is required to prevent immediate damage, as the RGP material can chip or scratch if dropped or mishandled during insertion and removal. Users must always wash and thoroughly dry their hands with a lint-free towel before touching the lenses to prevent the transfer of oils, debris, or microorganisms.
The cleaning routine involves two distinct steps: daily cleaning and disinfection. Daily cleaning typically uses a solution designed for rigid lenses, often requiring a gentle rub to remove protein and lipid deposits that accumulate on the lens surface during wear. Following this, the lenses must be soaked in a designated disinfecting solution, such as a hydrogen peroxide system or a specific multipurpose solution, for the required time period to neutralize bacteria and other pathogens.
It is necessary to use only preservative-free, sterile saline solution to fill the bowl of the lens before insertion. The filling solution must be sterile to avoid introducing contaminants into the vault space, which is in direct contact with the cornea. Never use tap water for rinsing or storage, as it contains microorganisms like Acanthamoeba that can cause severe, sight-threatening eye infections.