The Dr. Bill Takeshita Foundation

Last Modified: Sat, 18 Aug 2007

View other Common Causes of Vision Impairment

Keratoconus is a disease of the cornea and causes blurred sight, problems with glare, and distorted vision. The cornea is normally transparent and provides the eye with the majority of its focusing power. The cornea is the front most portion of the eye that a contact lens can be applied. In Keratoconus, the cornea is abnormally steep and the cornea is shaped similar to a cone rather than a sphere, hence the name Keratoconus.

In the early stages of the disease, patients may complain of itchy eyes and they may frequently rub their eyes. Their visual acuity may be marginally reduced to 20/25 or 20/30. As the condition progresses, visual acuity deteriorates and cannot be corrected with glasses. Rigid or hard contact lenses are required to improve the clarity of sight. Unfortunately, many cases of Keratoconus are progressive in nature and the transparency of the cornea reduces as stria or small whitish lines develop in the cornea, causing the cornea to be scarred. Patients with corneal scarring may have significant difficulty reading, seeing street signs or assignments written on the chalkboard. They may also complain of having difficulty seeing print that is written with a pencil or faded ink. Depth perception, and contrast vision are often affected and students may benefit from the following accommodations:

• Position students in the front portion of the class
• Provide students with copies of handouts of assignments normally presented on the board
• Large print books, bold lined paper, and the use of felt pens may be helpful
• Video magnifiers and hand magnfiers may be very helpful for reading

Approximately 10 percent of patients with Keratoconus will require a corneal transplant. The surgical success of corneal transplantation surgery among patients with Keratoconus is good. After surgery, many patients will require the use of contact lenses and glasses to maximize their vision. Sunglasses are often required to reduce problems with glare and bright light.

For more information, please see Low Vision Rehabilitation