Scleral lenses and rigid gas permeable (RGP) lenses offer unique benefits for patients with irregular corneas and specific ocular surface challenges. These specialty lenses are important options for people who cannot achieve clear or comfortable vision with standard soft contact lenses.
Scleral lenses are larger contact lenses designed to vault completely over the cornea. They rest on the sclera, which is the white part of the eye. This design creates a fluid reservoir between the lens and the cornea that continuously bathes the eye in preservative-free saline solution.
RGP lenses, also called rigid gas permeable lenses, are smaller hard lenses that contact the cornea directly. They create a smooth refractive surface by masking corneal irregularities. RGP lenses have been used since the late 1970s and remain effective for many vision correction needs.
The main difference between these lenses comes down to size and placement. Scleral lenses are larger and avoid touching the sensitive cornea entirely. RGP lenses are smaller and sit directly on the corneal surface. This distinction affects comfort, stability, and moisture retention.
Patients with dry eye often find relief with scleral lenses. The fluid reservoir continuously hydrates the cornea, reducing dryness and irritation throughout the day. RGP lenses depend on the natural tear film for lubrication, which may not provide enough moisture for people with dry eye.
Keratoconus causes the cornea to thin and bulge into a cone shape. Scleral lenses vault over this cone, creating a new smooth refractive surface and maintaining consistent vision even in advanced cases. At Insight Vision Center Optometry, Dr. Nathan Schramm, OD, FSLS, FBCLA has extensive experience fitting scleral lenses for keratoconus using advanced corneal mapping technology like the Pentacam.
High astigmatism requires lenses that offer precise correction and stable vision. Scleral lenses provide a smooth optical surface and excellent stability, often reducing residual astigmatism even in highly irregular corneas. Their larger size keeps them centered on the eye.
Scleral lenses offer superior stability during physical activities due to their larger diameter. They stay centered on the eye during rapid movements and intense exercise. RGP lenses may shift with blinking or quick eye movements, which could affect vision during sports.
Scleral lenses create a barrier that minimizes direct exposure to allergens. The fluid reservoir can also help flush out irritants. RGP lenses make direct contact with the cornea, which may trigger irritation when allergens are present in the environment.
Patients who have had LASIK, corneal transplants, or radial keratotomy may experience residual vision problems. Scleral lenses provide stability and can correct residual irregularities while protecting the cornea with a cushioning fluid reservoir. Dr. Thanh Mai, OD, FSLS, FIAOMC uses Pentacam corneal tomography to map these complex corneal surfaces.
For patients with mild to moderate corneal irregularities, RGP lenses can effectively mask surface distortions and deliver sharp vision. Their rigid design creates a smooth optical surface without requiring the larger scleral lens design.
Some children adapt more quickly to RGP lenses because of their simpler handling requirements. The shorter adaptation period can make them more practical for younger patients. However, children with significant corneal irregularities may still benefit from scleral lenses. Dr. Valerie Lam, OD, FAAO, FOVDR works with pediatric patients to determine the best lens option.
RGP lenses typically cost less than scleral lenses and may require fewer follow-up visits for fitting. For patients without severe dry eye or significant corneal irregularities, RGP lenses can provide excellent vision correction at a lower cost.
Scleral lenses often feel more comfortable from the start because they rest on the less sensitive sclera rather than the cornea. RGP lenses touch the cornea directly, which can cause a more noticeable foreign body sensation when you first begin wearing them.
The built-in fluid reservoir of scleral lenses continuously hydrates the eye, making them comfortable for extended wear. RGP lenses may become less comfortable over long hours due to reduced moisture retention and direct corneal contact.
Scleral lenses may take longer to master in terms of insertion and removal techniques. However, most patients find that once they learn proper handling, the comfort benefits make the adjustment worthwhile. RGP lenses are often easier to handle initially but may cause ongoing discomfort for some wearers.
Both lens types deliver excellent visual clarity. Scleral lenses create a smooth refractive surface by filling in corneal irregularities with the fluid reservoir. RGP lenses mask corneal imperfections with their rigid design. Both approaches result in sharp, clear vision for most patients.
Scleral lenses remain centered on the eye throughout the day, providing consistent vision without fluctuations. RGP lenses can shift slightly with blinking or rapid eye movements, which may momentarily affect visual clarity.
At Insight Vision Center Optometry, Dr. Nathan Schramm, OD, FSLS, FBCLA uses the Tomey WaveDyn Aberrometer to create wavefront-guided custom scleral lenses. These lenses can correct higher-order aberrations that affect the overall quality of vision. Standard RGP lenses may not address all higher-order issues in complex cases.
Scleral lenses rest on the sclera, which has far fewer nerve endings than the cornea. This reduces irritation and discomfort. RGP lenses contact the highly sensitive cornea directly, which can cause more awareness of the lens on the eye.
The space between a scleral lens and the cornea fills with preservative-free saline solution. This fluid reservoir hydrates the eye and fills in surface irregularities. RGP lenses do not vault over the cornea, so they lack this built-in hydration system.
Scleral lenses are typically custom designed using detailed mapping of both the cornea and surrounding sclera. Technologies like EyePrintPRO can create an exact impression of the eye surface for a precise fit. RGP lenses can be customized, but their smaller size limits how much they can accommodate complex corneal shapes.
The larger diameter of scleral lenses creates a broader optic zone, which enhances peripheral vision. RGP lenses have a smaller diameter that may restrict the peripheral field of view.
Patients with Sjogren's syndrome, ocular graft-versus-host disease, or Stevens-Johnson syndrome often experience severe dryness that standard lenses cannot address. The continuous fluid reservoir of scleral lenses provides ongoing lubrication that can significantly improve comfort and protect the corneal surface.
Corneal dystrophies cause irregular changes to the corneal surface. Scleral lenses vault over this irregularities, creating a smooth optical surface that enhances visual clarity. Dr. Nhi Nguyen, OD works with patients who have complex corneal conditions to find the right lens solution.
Some patients experience visual problems after LASIK, PRK, or radial keratotomy. Scleral lenses can correct residual refractive errors and address dry eye symptoms that sometimes develop after these procedures.
Most patients adapt to scleral lens comfort within a few days, though learning insertion and removal techniques may take one to two weeks of practice. RGP lenses often have a shorter handling learning curve, but the foreign body sensation on the cornea may take several weeks to diminish.
Neither scleral nor RGP lenses are typically approved for overnight wear. Both types should be removed before sleeping to allow your eyes to receive adequate oxygen and to prevent complications. Your eye doctor will provide specific wear time recommendations based on your individual needs.
Scleral lenses require filling with preservative-free saline before insertion. Both lens types need daily cleaning with appropriate solutions. Scleral lenses should be stored in conditioning solution overnight. Your eye doctor will provide detailed care instructions specific to your lenses.
Coverage varies by insurance plan and medical necessity. Scleral lenses prescribed for medical conditions like keratoconus may be covered differently than lenses prescribed for routine vision correction. Contact your insurance provider for specific coverage details.
With proper care, both scleral and RGP lenses can last one to two years or longer. The durability depends on how well you maintain them and whether your prescription changes. Regular follow-up appointments help ensure your lenses remain in good condition.
Yes, children can successfully wear scleral lenses when appropriate for their condition. The decision depends on the child's maturity, ability to handle the lenses, and specific vision needs. Pediatric patients with conditions like keratoconus or severe corneal irregularities may benefit significantly from scleral lenses.
