Do you remember in old cartoons when a character would see a delicious plate of food and his eyes would comically bulge out like footballs?
That pointed cone shape of the eye in such scenes isn’t much different from the effects of keratoconus, a vision disorder in which the cornea (the front part of the eye) goes from being its normal rounded shape to thinner and more pointed.
Cornea Shape And Vision
The different structures of our eyes need to have very specific shapes in order to reflect light onto the light-sensitive retina and enable us to see clearly. The reason many people need glasses at an early age is that their eyes are too long or too short. This makes the image reflected through the lens fall in front of the retina or behind it, making images blurry at different distances.
With keratoconus, because of the misshapen cornea, the image reflected through the lens of the eye becomes distorted at any distance, producing multiple images or warping them before they reach the retina.
Symptoms And Progression Of Keratoconus
In early stages, keratoconus results in slightly blurred and distorted vision, as well as sensitivity to light and glare. Typically these symptoms will appear in the late teens or 20s, and may progress for up to twenty years before slowing. As keratoconus worsens, it can produce double vision, multiple images, glare around lights, and poor night vision.
In rare cases, the thinned cornea may develop a tiny crack because of the strain of the cone-like shape. When a crack forms, the cornea will swell, significantly impacting vision for weeks or months as it heals, leaving a scar behind that also impacts vision.
Vision Correction For Keratoconus
While there are no medications that can prevent keratoconus from progressing, its effects on vision are correctable with glasses or contact lenses in the early stages. Because the eye’s shape is changing over time, these may not fully correct the problem in the later stages, but rigid gas permeable lenses can still produce significant improvements. Regular eye appointments are very important to make sure contact lenses fit properly and continue to correct vision. In particularly severe cases, a corneal transplant may become necessary.
Your optometrist looks forward to seeing you!
Find a Vision Source® practice near you using our search tool.