Keratoconus is a progressive eye disease that causes a thinning of the clear front surface of the eye (cornea) and distorts the cornea into a cone-like shape. Keratoconus causes distorted vision that cannot be corrected with eyeglasses. Most cases of keratoconus become apparent during a person's teens or early 20s.

We see through the cornea, which is the clear outer lens or "windshield" of the eye. Normally, the cornea has a dome shape, like a ball. Sometimes, however, the structure of the cornea is just not strong enough to hold this round shape and the cornea bulges outward and downward like a cone. This condition is called keratoconus

Manocha Eye Hospital caters to a significent number of Keratoconus patients every year

What causes Keratoconus?

Tiny fibers of protein in the eye called collagen help hold the cornea in place and keep it from bulging. When these fibers become weak, they cannot hold the shape and the cornea becomes progressively more cone shaped.

Keratoconus is caused by a decrease in protective antioxidants in the cornea. The cornea cells produce damaging by-products, like exhaust from a car. Normally, antioxidants get rid of them and protect the collagen fibers. If antioxidant levels are low, the collagen weakens and the cornea bulges out.

Keratoconus is genetic, so it can run in families. If you have it and have children, it’s a good idea to have their eyes checked for it starting at age 10. The condition progresses more rapidly in people with certain medical problems, including certain allergic conditions. It could be related to chronic eye rubbing.


  • A sudden change of vision in one eye
  • Double vision when looking with just one eye
  • Objects both near and far looking distorted
  • Bright lights looking like they have halos around them
  • Lights streaking
  • Seeing double or triple ghost images
  • Being uncomfortable driving due to blurry vision, especially at night

How Is Keratoconus Diagnosed?

Keratoconus changes vision in two ways:

  • As the cornea changes from a ball shape to a cone shape, the smooth surface becomes distorted. This is called irregular astigmatism.
  • As the front of the cornea expands, vision becomes more nearsighted. That is only up close objects can be seen clearly. Anything too far away will look like a blur.

What is the treatment

Treatment usually starts with new eyeglasses. If eyeglasses don't provide adequate vision, then contact lenses, usually rigid gas permeable or scleral contact lenses, may be recommended. With mild cases, new eyeglasses can usually make vision clear again. Eventually, though, it will probably be necessary to use contact lenses or seek other treatments to strengthen the cornea and improve vision.


A treatment called cornea collagen crosslinking is often effective to help prevent worsening. Intacs are implants that are placed under the surface of the cornea to reduce the cone shape and improve vision.


A specialized laser procedure called PTK can smooth out a raised scar (like a callus) and improve contact lens comfort.


If eyeglasses and contact lenses no longer provide stable and comfortable good quality vision, a cornea transplant can be performed. This involves removing the center of the cornea and replacing it with a donor cornea that is stitched into place. This is typically only done as a last resort.

Treatments Available at Manocha Eye Hospital

Myths / Frequently Asked Questions

1What Kinds of Specialized Lenses Can Correct Keratoconus?
Answer: Reverse geometry contacts include a reversed curve that compensates for the visual distortion introduced by unusually elongated corneas. Scleral lenses extend over the entire cornea in a steady curve, correcting for corneal distortion without actually touching or resting on the cornea itself.
2Can Eyeglasses and Soft Contacts Correct Keratoconus?
Answer: Eyeglasses and regular soft contacts are limited in their ability to correct anything beyond the earliest stages of keratoconus. Most patients will get better results from gas permeable contacts (or hybrid soft contacts, which have a rigid center area) that hold their curvature independent of the corneal surface.
3Who Gets Keratoconus, and Why?
Answer: Keratoconus tends to make its first appearance early in adulthood, for reasons that are not well understood. Inherited traits, excessive eye rubbing, and thin or weak corneal tissues may all be involved in its development or severity.
4I was told RGP (rigid gas permeable contacts) will stop keratoconus from worsening. Is this true?
Answer: No, this old wives' tale is not true. When worn, the RGP lenses temporarily flatten the non-structural epithelium (skin) of the cornea. This creates the illusion of stopping the progression. The keratoconus continues to progress, and contacts must be updated to keep up with the worsening disease.
To say that RGP contact lenses somehow stop keratoconus from progressing is like saying that wearing a baseball hat stops a child's skull from growing. Because keratoconus is a progressive disease, there must be some medical intervention to stop it, such as corneal crosslinking.
5Intacs are referred to as prescription inserts. Does this mean that they will eliminate my need for contacts or glasses?
Answer:Good question. To start, we should clarify that Intacs are not like contact lenses. They are curved, clear plastic half-moon-shaped segments that are inserted under the surface of the cornea to reduce the steepness of the cornea by reshaping it.
They are referred to as "prescription inserts" because they are available by prescription only, meaning that they must be ordered and inserted by a trained surgeon. The Intacs themselves have no prescription and are not intended to provide vision correction.
In cases where patients have a very slight prescription, the need for glasses and/or contacts can be eliminated; however, we tell patients not to expect this as a result. What you can expect is a much easier time being fitted for glasses and contacts, and also possibly a wider variety of contact lens types to choose from.
6I've heard about corneal collagen crosslinking treatment. Will this improve my vision?
Answer: The primary goal of corneal cross-linking (CXL) is to strengthen and stabilize the cornea to prevent progression of keratoconus. In some cases, CXL may also improve corneal shape and reduce corneal astigmatism, and thereby improve uncorrected and best-corrected visual acuity. But there's no guarantee this additional benefit will occur.
7Will I go blind from keratoconus?
Answer:Keratoconus does not typically lead to complete blindness. But the disease can degrade vision to a level where one will experience difficulty leading a normal life.
Corneal hydrops (extensive scarring) as well as contact lens intolerance can occur as the disease progresses. This can lead to legal blindness and will eventually lead to the need for a cornea transplant.
8I'm totally confused about this: Is my cornea an oval shape or is my eye an oval shape if I have keratoconus?
Answer:With keratoconus, the cornea (the clear front surface of the eye) loses its essentially spherical shape and becomes progressively elongated, like the tip of an American football or a rugby ball. The rest of the eyeball retains its normal shape.
9Does this eye condition cause night blindness and make it hard to see when driving?
Answer:Keratoconus can result in difficulty driving at night from starbursts, glare, halos and multiple images.
10Does early diagnosis make any difference in keratoconus progression?
Answer:Definitely. Early diagnosis means vision may be only minimally affected. In those cases, corneal crosslinking should be considered to stabilize and prevent future vision loss.
11I was told by my doctor that I am in the moderate stage of keratoconus. I have started using RGP lenses. Can you please tell me whether RGP lenses reduce the progression of the disease and what the side effects are of wearing RGP lenses?
Answer:Some doctors mistakenly tell patients that RGP contact lenses halt the disease from progressing. This is like saying a baseball cap will prevent a skull from expanding. The only proven method to halt progression is with corneal collagen crosslinking.
12Can you go blind if you have keratoconus?
Answer:It's possible to lose vision to the point of being legally blind (20/200 vision or worse).