Scleral Lenses 101: What They Are and How They Work

Introduction

When it comes to vision correction, many people are familiar with eyeglasses and traditional contact lenses. However, for individuals with certain eye conditions, a specialized solution is needed. Scleral lenses are an advanced type of contact lens designed to offer superior comfort and clarity, especially for those with irregular corneas, dry eye syndrome, and other vision issues. Unlike conventional lenses, these lenses provide a unique fit and function, making them a game-changer for people who struggle with traditional options. This article explores what scleral lenses are, how they work, their benefits, and why they might be the right choice for you.

What Are Scleral Lenses?

Scleral lenses are large-diameter, gas-permeable contact lenses that vault over the cornea and rest on the sclera, the white part of the eye. Unlike standard contact lenses that sit directly on the cornea, scleral lenses create a tear-filled reservoir between the lens and the cornea. This design offers several advantages, including improved hydration, enhanced vision, and increased comfort.

Scleral lenses range in size from about 14mm to over 20mm in diameter, significantly larger than standard soft or rigid gas-permeable (RGP) lenses. The large size makes them more stable on the eye, reducing the risk of lens displacement or discomfort.

How Do Scleral Lenses Work?

Scleral lenses work by forming a smooth optical surface over the cornea, correcting refractive errors such as nearsightedness, farsightedness, and astigmatism. The lens’s structure helps compensate for corneal irregularities, making it particularly beneficial for individuals with conditions like keratoconus, post-surgical corneas, or corneal scarring.

The key working mechanisms of scleral lenses include:

Vaulting Over the Cornea: Unlike regular lenses that rest directly on the cornea, scleral lenses arch over it, preventing direct contact and protecting the corneal surface.
Tear Reservoir: The space between the lens and the cornea is filled with a saline solution that keeps the eye moist and reduces dryness, providing comfort for individuals with severe dry eye syndrome.
Stable Fit: Their larger size prevents the lenses from shifting or falling out, making them ideal for individuals with high prescriptions or corneal abnormalities.
Oxygen Permeability: Despite their size, scleral lenses are made from gas-permeable materials that allow oxygen to reach the cornea, ensuring eye health.

Who Can Benefit from Scleral Lenses?

Scleral lenses are designed to assist individuals with various eye conditions, including:

Keratoconus: A progressive eye disorder where the cornea thins and bulges into a cone shape, leading to distorted vision.
Severe Dry Eye Syndrome: Conditions such as Sjögren’s syndrome or graft-versus-host disease (GVHD) can cause extreme dryness, which scleral lenses help alleviate by maintaining a tear film.
Post-Surgical Corneas: After procedures like LASIK, PRK, or corneal transplants, some individuals experience irregular corneal surfaces that benefit from scleral lenses.
Corneal Scarring or Irregularities: Trauma, infections, or degenerative conditions can result in corneal scars that impair vision.
High Refractive Errors: Those with extreme myopia, hyperopia, or astigmatism may achieve better vision correction with scleral lenses compared to standard contacts.
Athletes and Active Individuals: Due to their stability, scleral lenses are suitable for individuals who engage in sports or outdoor activities where conventional lenses may shift or fall out.

Benefits of Scleral Lenses

Scleral lenses offer several advantages over traditional contact lenses and eyeglasses:

Improved Vision: They create a smooth optical surface, reducing distortion and providing sharper vision, especially for those with corneal irregularities.
Enhanced Comfort: The tear-filled reservoir keeps the eyes hydrated, reducing discomfort associated with dry eye syndrome.
Longer Wearing Time: Many users find that they can comfortably wear scleral lenses for extended periods without experiencing irritation.
Stability: Their large diameter ensures that they remain in place throughout the day, minimizing the risk of displacement.
Protection: By vaulting over the cornea, scleral lenses shield the eye from external irritants, including dust, wind, and allergens.
Customization: Each pair of scleral lenses is custom-made to fit the unique shape of the patient’s eye, ensuring a precise and comfortable fit.

Fitting and Customization Process

Unlike standard contact lenses, scleral lenses require a specialized fitting process conducted by an eye care professional. Here’s what to expect:

Comprehensive Eye Exam: The optometrist or ophthalmologist evaluates your cornea, sclera, and overall eye health to determine whether scleral lenses are suitable for you.
Measurements and Molding: Advanced imaging technology is used to map the surface of your eye, ensuring a precise lens fit.
Trial Lenses: You may be given trial scleral lenses to assess comfort and effectiveness before the final lenses are made.
Lens Ordering and Adjustments: Once the ideal fit is determined, custom lenses are ordered, and adjustments may be made based on feedback.
Training and Care Instructions: The eye care professional will provide guidance on inserting, removing, and maintaining your lenses properly.

How to Care for Scleral Lenses

Proper care is essential to maintaining the longevity and effectiveness of scleral lenses. Here are key steps:

Cleaning: Use a recommended cleaning solution to remove debris and protein buildup daily.
Rinsing: Always rinse lenses with a preservative-free saline solution before inserting them.
Storage: Store lenses in a sterile case filled with a disinfecting solution overnight.
Hand Hygiene: Wash and dry hands thoroughly before handling lenses to prevent contamination.
Regular Check-Ups: Visit your eye care professional regularly to ensure proper lens fit and eye health.

Common Challenges and Solutions

While scleral lenses offer numerous benefits, some users may encounter challenges:

Insertion and Removal: Initially, placing and removing scleral lenses may be tricky. Using a plunger tool and practicing proper techniques can help.
Lens Fogging: Some users experience lens fogging, which can be reduced by improving lens hygiene and using recommended anti-fogging drops.
Bubble Formation: Air bubbles trapped beneath the lens can cause discomfort. Ensuring lenses are filled properly with saline before insertion helps prevent this issue.
Adjustment Period: It may take a few days to weeks for users to adapt to the sensation of wearing scleral lenses.

Conclusion

Scleral lenses are a revolutionary option for individuals who struggle with traditional contact lenses or glasses due to corneal irregularities, severe dry eye syndrome, or other vision challenges. Their unique design, which includes a tear-filled reservoir and a stable fit, offers unparalleled comfort and clarity. While the fitting process and care routine may require extra effort, the benefits far outweigh the challenges for many users. If you have been searching for a solution to persistent vision problems, consulting an eye care professional about scleral lenses might be the best step toward achieving clearer, more comfortable vision.