Keratoconus: Symptoms

and Stages



Overview  |  Symptoms  |  Diagnosis  |  Risk Factors  |  FAQs

Your cornea – the clear layer at the front of your eye – is usually dome-shaped. However, keratoconus causes the cornea to bulge outwards, in the shape of a cone. You may have no symptoms in the early stages. Though as the condition progresses, your vision may become slightly blurred. 

Keep reading to learn more about the symptoms and causes of keratoconus, and how we diagnose it.

What is keratoconus?

Keratoconus is a progressive eye condition with no known way of preventing it. It affects roughly 1 in every 2000 people and commonly starts to develop around puberty, between ages 10 and 25.

As the condition progresses, your vision will become poorer as your prescription changes and astigmatism worsens.

It is often more noticeable in one eye than the other, though it usually affects both eyes. It may progress slowly over several years.

If your vision worsens suddenly, speak to one of our ophthalmologists (eye specialists) for advice. A sudden vision change should always be assessed by a medical professional. Contact us for assistance.

Symptoms of keratoconus

In its earliest stages, people with keratoconus are often unaware they have it as they experience no obvious symptoms.

Your symptoms will become more noticeable and severe as the condition develops.

Keratoconus stages

During stage 1, you may find it harder to see at a distance (short-sightedness), and your vision may be blurry. You might also experience symptoms of astigmatism, including eye strain, headaches, and difficulty concentrating on close-by objects. You might find that you need to squint to see clearly.

At stage 2, however, you may experience the above symptoms as well as those listed below.

Signs and symptoms include:

  • Blurry vision
  • Increasingly poor vision
  • Double vision in one eye (monocular diplopia) or both eyes
  • Glare and ‘halos’ around light
  • Sensitivity to light (photophobia)
  • Difficulty seeing at night
  • Eye irritation or headaches
  • Frequent change in glasses prescription
  • Irregular astigmatism
  • Scarring of the cornea
  • Thinning of the cornea

In the final stage, stage 3, your symptoms will likely be more severe. Your vision might worsen considerably, and you may be more sensitive to light. The bulging of your cornea may also be more noticeable.

If these symptoms sound familiar, speak to one of our ophthalmologists (eye specialists). We will assess your symptoms to determine the possible causes.

Getting an early consultation can prevent loss of vision and further damage to your cornea which is inevitable as the condition progresses.

Diagnosing keratoconus

As the early stages show no symptoms, we often diagnose it during an assessment for laser vision correction procedures. Though, your optician may diagnose it during a routine eye exam and recommend a referral to an ophthalmologist. 

If you already had a diagnosis of astigmatism that is changing rapidly, we would screen for keratoconus. In our initial consultation, we will assess your eyes and symptoms. This includes checking for refractive errors and whether you need glasses. We will go through risk factors, such as eye rubbing and a family history of keratoconus.

We will also perform scans of your cornea. The most accurate method of diagnosis is using AI-powered corneal scans. These provide a detailed analysis of the structure of your cornea. Mr Tariq Ayoub will explain your assessment results and the most appropriate treatment options if you have keratoconus.

Watch our videos of Mr Ayoub explaining the causes of keratoconus.

Other risk factors include:

  • Being black or Latino
  • Certain disorders, such as Down syndrome and Ehlers-Danlos syndrome
  • Chronic eye inflammation; can occur due to allergies, asthma, etc.
  • Age – starting around puberty

Anyone can get keratoconus, though these risk factors can increase the likelihood of getting it. If you fit into one or several of these categories, pay close attention to keratoconus symptoms.

Visit our keratoconus treatment page to learn more about treatment options.

Book an appointment

As keratoconus develops, it can lead to a severe loss of vision, corneal thinning and scarring. 

Speak to our eye specialist early if you’re showing the signs and symptoms of keratoconus. Our experienced specialists diagnose keratoconus using AI-powered technology. 

Book a consultation with our experts today to arrange an assessment and testing.

If you’re worried that another eye specialist has missed your symptoms, we offer a second opinion service to put your mind at ease.

Contact us


    This will depend on your role’s requirements and your current treatment. As your prescription can often change with keratoconus, you may need frequent eye tests to ensure your treatment plan is up to date. Some jobs require a certain level of visual accuracy which can be affected if your treatment is insufficient.

    With the appropriate treatment, your keratoconus should not affect your driving ability. As long as you meet the DVLA’s minimum required standard, you can drive. Glasses, contact lenses, or surgical treatment can help you meet the DVLA’s minimum required standard.

    As effective treatments are available for each stage, keratoconus is not usually considered a disability. However, if your vision is significantly affected and cannot be improved, you may be able to register as vision-impaired. Though, we consider the resulting vision loss a disability, not your condition.

    While you cannot prevent keratoconus, you can take steps to slow the condition’s progress.

    • Avoid rubbing your eyes
    • Follow your eye specialist’s treatment plan
    • Wear sunglasses in the sun to protect your eyes
    • Wear eye protection while swimming and during necessary activities
    • Visit your eye specialist as soon as you notice changes in your vision
    • Attend regular eye appointments if you have family members with keratoconus

    Yes, various factors can affect your balance when you have keratoconus.

    These include:

    • Different lenses
    • Loss of depth perception
    • High amounts of astigmatism
    • Unequal vision leading to dizziness

    Your visual system and the inner ear influence your balance. If your visual system is impacted, in any way, you may feel a sense of imbalance.

    Corneal topography scans are a computer-assisted method of diagnosing a corneal condition. Topography refers to the physical features of any area. 

    During a corneal topography scan, we create a 3D image of your cornea’s shape and curvature. This allows us to check for corneal diseases and irregularities, such as swelling, scarring, and deformities.

    You may also require additional corneal scans, including corneal OCT and epithelial mapping scans, as part of your assessment.

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