What is keratoconus?
The is the clear front window of the eye. In , this window slowly thins and bulges outward into a cone shape. Because the cornea provides most of the eye's focusing power, its irregular shape distorts vision in a way that glasses often cannot fully correct.
The cornea is the clear front window of the eye; in keratoconus it thins and bulges outward. Drag to explore.
3D model: NIH 3D / HuBMAP Human Reference Atlas (3DPX-020963), CC BY 4.0
The condition usually appears in the teens or twenties and can run in families. Allergies and frequent, forceful eye rubbing are strongly linked to it. If you have keratoconus, protecting your eyes from rubbing is one of the most useful things you can do.
What does it feel like?
- Blurred or distorted vision that glasses do not fully fix
- Frequent changes in your glasses prescription
- Ghosting, double images, or streaks around lights, especially at night
- Increased sensitivity to light
Simulated view: Normal vision. This is roughly how the scene looks with a healthy, evenly curved cornea.
This is roughly how the scene looks with a healthy, evenly curved cornea.
An approximate illustration of how keratoconus can change vision — ghosting and starbursts around lights are often most noticeable at night. Every person's experience is different.
Following the disease
Keratoconus can progress over years, especially in younger patients. We track it with repeated corneal mapping ( and tomography), which measures the shape and thickness of the cornea with great precision. These maps tell us whether the cone is stable or moving.
Treatments, step by step
- (CXL): riboflavin (vitamin B2) drops are applied to the cornea, followed by carefully measured ultraviolet light. This strengthens the collagen framework of the cornea and aims to stop the disease from progressing. It does not reverse the cone, which is why earlier treatment is better.
- Special contact lenses: rigid gas-permeable, hybrid, or rest on the eye and create a smooth new surface, often giving sharper vision than glasses can.
- : small, clear arcs placed within the cornea can flatten and regularize its shape in selected eyes, improving contact lens fit and vision.
- Corneal transplant: when the disease is advanced or scarring blocks vision, we replace the diseased layers. In deep anterior lamellar keratoplasty (DALK), only the front layers are replaced while your own healthy inner layer is kept, which lowers the risk of rejection compared with a full-thickness transplant.
Living with keratoconus
A few habits make a real difference. Treat your allergies so your eyes itch less, and never rub them, because rubbing can push the disease forward. Keep your follow-up appointments even when your vision feels stable, since the corneal maps can show change before you notice it. And if you wear rigid or scleral lenses, good cleaning and wearing habits protect both comfort and corneal health.
Many patients need only cross-linking and a good contact lens. Surgery is reserved for the cases that truly need it, and we discuss every option honestly before deciding. The key message is hopeful: keratoconus is a disease we can usually stop, and with modern lenses and, when needed, modern surgery, most patients keep good, useful vision for life.
Key points
- Keratoconus thins and bulges the cornea into a cone shape, distorting vision in a way that glasses often cannot fully correct.
- It usually appears in the teens or twenties; allergies and forceful eye rubbing are strongly linked to it — never rub your eyes.
- Regular corneal mapping shows whether the cone is stable or moving, often before you notice any change.
- Cross-linking can stop the disease from progressing, and special contact lenses such as scleral lenses can restore sharp vision.
- The outlook is hopeful: keratoconus can usually be stopped, and most patients keep good, useful vision for life.
Whether this applies to you can only be decided after an examination.