What is keratoconus?
Keratoconus is a condition in which the cornea thins and becomes progressively more cone-shaped, which distorts vision and cannot be fully corrected with ordinary glasses in many cases.
- Subject
- Eye conditions
- Topic
- Keratoconus
- Kind of question
- What is…
- Last reviewed
- 22 September 2026
In more detail
It usually appears in the teenage years or early twenties. Because it progresses, the important part of management is detecting it and monitoring it rather than simply correcting the vision it causes today.
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It is one of 483 answers in the vision and eye health knowledge base, filed under Eye conditions & diseases in Keratoconus . The subject page carries the answers either side of it, and the hub is searchable.
Subjects this question touches
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- Condition Glaucoma
- Condition Keratoconus
- Condition Retina and macula conditions
- Condition Diabetic eye disease
- Condition Eye infections, allergies and injuries
This information is for educational purposes and does not replace an examination by a qualified eye-care professional.
General answers cannot tell you what is happening in your own eyes. Only an examination by a qualified ophthalmologist can do that.
Sources & further reading
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- Eye Health Information
Condition-by-condition eye health information from a US government research institute, written for patients rather than for clinicians.
Used for Plain-language explanations of eye conditions and their symptoms; Healthy vision and screening guidance.
Link checked 23 September 2026
- EyeSmart: eye health information for the public
Patient-facing material from the largest ophthalmology professional body, covering conditions, tests and treatments outside refractive surgery.
Used for Cross-checking patient-facing explanations of non-refractive eye conditions; Describing what tests such as dilation and OCT involve.
Link checked 23 September 2026