• Facility VOG
  • Doctor Dr. Dennis Lin
  • Service Keratoconus, Scleral Lens
  • Location Monterey Park, CA

Keratoconus is a progressive corneal eye disease in which the thickness of the cornea thins and the curvature begins to bulge into a steeper cone-like shape. This cone shape cornea causes light to scatter and defocus causing distorted vision.

In early stages, keratoconus causes slight blurred, distorted vision, and glare with increased light sensitivity.  Keratoconus often starts in the teenage years to early 20’s.  Often patients with good vision throughout their earlier life now suddenly and drastically have decreased vision.  Each eye may have different severity of keratoconus.

Often, keratoconus patients experience is large fluctuation in their eyeglasses prescription and often times unhappy with their eyeglasses as the fluctuating eyeglass prescription can cause eyestrain and headaches.

Keratoconus have a genetic link and a hereditary component.  It can run in families therefore it is a good idea to have family members screened for this condition.


Eyeglasses or soft contacts may be used to help patients see clearer in early stages.  As the disorder progresses by steeping and thinning of the cornea, rigid gas permeable contacts and scleral lenses may be the next step to improving the quality of vision.

Scleral lenses vaults over the irregularly shaped cornea.  There is no applied pressure to the weakened cornea and no mechanical or physically rubbing of the scleral lenses on the apex of cornea therefore creating a more comfortable fit.  Scleral lenses are designed to help vision improvement with mild, moderate, and severe stages of keratoconus.

Scleral lenses are more stable than conventional gas permeable contact lenses.

These lenses are custom made-to-order soft contacts for mild to moderate keratoconus eyes and may be more comfortable than rigid gas permeable and/or hybrid contact lenses for some wearers.

If eyeglasses and soft contact lenses are not able to provide adequate vision, rigid gas permeable contact lenses may be able to provide better quality of vision. Gas permeable lenses rests gently and lightly on the cornea, replacing its irregular shape with a smoother, uniform refracting surface to improve vision.

Fitting contact lenses on an eye with keratoconus is often challenging and time-consuming. Expect frequent return visits to your eye care provider for modifications especially if the keratoconus is progressing.

Rigid gas permeable contact lens resting over a steep cone-shaped cornea can sometimes be uncomfortable for a person with keratoconus.  Some practitioners may utilize a piggyback method. This method involves placing fitting a rigid gas permeable lens over a soft lens on the cornea. This approach increases wearer comfort because the soft lens acts like a cushioning pad under the rigid GP lens.

These lenses are designed specifically for keratoconus with a central rigid gas permeable material with a soft peripheral “skirt” for increased comfort.


Corneal collagen cross-linking or CXL, strengthens corneal tissue to halt bulging of the eye’s surface in keratoconus.

Intacs are arc-shape corneal inserts that are surgically positioned within the peripheral cornea to reshape the front surface of the eye for clearer vision.  These corneal implants are removable and reversible and the procedure takes about 10 minutes.

Intacs might delay but can’t prevent a corneal transplant if keratoconus continues to progress.

In severe cases of keratoconus, some patients may not be able to tolerate a rigid contact lens, or they reach the point where contact lenses or other therapies no longer provide acceptable vision.  At this point, a corneal transplant called a penetrating keratoplasty may be an option. Even after a transplant, you will still need glasses or contact lenses to improve quality of vision

  • An eye doctor may uncover the disease during an eye exam. Symptoms of keratoconus may be discussed during the exam which include:
  • A sudden change of vision in one eye.
  • Double vision when looking with just one eye
  • Objects distorted at distance and near
  • Haloes and glare around light sources especially at low light conditions.
  • Seeing ghost images
  • Eyestrain and/or uncomfortable vision due to blurry vision


This diagnostic instrument allows the doctor to analyze the shape of your corneal and helps in diagnosing keratoconus.

This diagnostic instrument measures and analyzes the thickness of the corneal in different sections throughout the cornea.