Introduction

Keratoconus is a progressive eye condition that affects the cornea, the clear, dome-shaped surface at the front of the eye. Instead of maintaining its normal rounded shape, the cornea gradually becomes thinner and more cone-shaped.

This change can cause increasingly blurred or distorted vision and may make glasses less effective over time.

Keratoconus often develops during the teenage years or early adulthood, although it can occur at other ages. The condition can progress at different rates, and early diagnosis is important because treatments are available that can help slow or stop progression and preserve vision.

In this guide, we’ll explain what keratoconus is, its symptoms and causes, how it is diagnosed, and the treatment options available.

What Is Keratoconus?

The cornea plays an important role in focusing light onto the retina. For clear vision, its shape needs to remain regular.

With keratoconus, the cornea becomes progressively:

• Thinner
• Weaker
• More irregular
• Cone-shaped

This irregular shape can cause light to focus incorrectly on the retina, resulting in irregular astigmatism and visual distortion.

Keratoconus can affect one or both eyes, although the severity may differ between the two eyes.

What Does Keratoconus Do to Your Vision?

As the cornea changes shape, vision can become increasingly difficult to correct with standard glasses.

You may notice:

• Blurred vision
• Distorted vision
• Increasing astigmatism
• Frequent changes in glasses prescription
• Difficulty seeing clearly at night
• Halos around lights
• Increased sensitivity to light
• Reduced contrast
• Difficulty driving at night

Some people notice that their vision changes relatively quickly, while others experience gradual progression over several years.

Early Symptoms of Keratoconus

Keratoconus can be difficult to recognise in its early stages because symptoms may initially resemble ordinary short-sightedness or astigmatism.

Early warning signs include:

Frequently Changing Glasses Prescription

If your prescription changes repeatedly, particularly if astigmatism is increasing, your eye doctor may recommend additional corneal testing.

Increasing Blurred Vision

Vision may remain blurred even after updating your glasses prescription.

Distorted Vision

Straight lines may appear slightly distorted or irregular.

Poor Night Vision

Some people experience increasing glare, halos, or difficulty seeing clearly in low-light conditions.

Difficulty With Contact Lenses

As the cornea becomes more irregular, standard soft contact lenses may become less effective or comfortable.

What Causes Keratoconus?

The exact cause of keratoconus is not fully understood. It is likely to result from a combination of genetic, environmental, and biological factors.

Genetics

Keratoconus can run in families.

Having a close relative with keratoconus may increase your risk.

Eye Rubbing

Frequent or vigorous eye rubbing is associated with keratoconus and may contribute to progression in susceptible individuals.

Children and adults with allergies may be particularly prone to eye rubbing because of persistent itching.

If your eyes are frequently itchy, treating the underlying allergy or irritation is important.

Allergies and Atopic Conditions

People with conditions associated with allergic eye disease may have an increased risk of developing keratoconus.

Managing eye allergies can help reduce the urge to rub the eyes.

Other Factors

Research suggests that several biological and environmental factors may contribute to corneal weakening. However, there is no single cause that explains every case.

Who Is at Risk of Keratoconus?

Keratoconus can affect anyone, but certain factors may increase the likelihood of developing it.

These include:

• Family history of keratoconus
• Frequent eye rubbing
• Allergic eye disease
• Certain genetic conditions
• Childhood or teenage onset of progressive astigmatism

Because keratoconus often develops relatively early in life, changes in vision during adolescence should not be ignored.

Can Keratoconus Affect Children?

Yes.

Keratoconus can develop during childhood and may progress more rapidly in younger patients.

Parents should arrange an eye examination if a child:

• Frequently changes glasses prescriptions
• Continually rubs their eyes
• Has worsening astigmatism
• Complains that vision remains blurry despite glasses
• Has difficulty seeing at night

Early diagnosis is particularly valuable because corneal cross-linking can be used in appropriate patients to slow or stop progression.

How Is Keratoconus Diagnosed?

A routine eye examination may detect clues suggesting keratoconus, but specialised corneal testing is usually needed to confirm the diagnosis and assess progression.

Visual Acuity Testing

This determines how clearly you can see at different distances.

Refraction

Your eye care professional measures your prescription and checks for changes in:

• Myopia
• Astigmatism
• Other refractive errors

An unusual or rapidly changing prescription may raise suspicion of keratoconus.

Slit-Lamp Examination

A slit lamp allows the ophthalmologist to examine the cornea under magnification.

In more advanced cases, signs of corneal thinning or scarring may be visible.

Corneal Topography

Corneal topography creates a detailed map of the cornea’s curvature.

It can identify areas of abnormal steepening and irregularity.

Corneal Tomography

Corneal tomography provides more detailed information about both the front and back surfaces of the cornea as well as its thickness.

It can help detect early keratoconus and assess whether the condition is progressing.

Why Early Diagnosis Matters

Keratoconus is progressive, meaning the shape and strength of the cornea can change over time.

Without monitoring or appropriate treatment, progression may lead to:

• Increasingly irregular vision
• Difficulty correcting vision with glasses
• Dependence on specialised contact lenses
• Corneal scarring
• Significant reduction in visual quality

Early detection allows your ophthalmologist to monitor the cornea and determine whether treatment is needed.

Keratoconus Treatment Options

Treatment depends on:

• Stage of keratoconus
• Whether the condition is progressing
• Corneal thickness
• Vision quality
• Contact lens tolerance
• Presence of corneal scarring

Treatment does not necessarily mean surgery. Many people can manage keratoconus effectively with glasses or specialised contact lenses.

1. Glasses

In the early stages, glasses may provide adequate vision correction.

However, as the cornea becomes more irregular, glasses may no longer provide sufficiently clear vision.

2. Contact Lenses

Specialised contact lenses can improve vision by creating a smoother optical surface over the irregular cornea.

Options may include:

• Rigid gas-permeable (RGP) lenses
• Scleral lenses
• Hybrid lenses
• Specialised soft lenses

Scleral lenses are larger lenses that rest on the white part of the eye and vault over the cornea, creating a fluid reservoir between the lens and corneal surface.

A contact lens specialist can determine which design is most appropriate.

3. Corneal Cross-Linking

Corneal cross-linking (CXL) is an important treatment for progressive keratoconus.

The procedure strengthens the corneal tissue by using riboflavin (vitamin B2) and ultraviolet-A (UVA) light to create additional bonds between collagen fibres.

The primary goal of cross-linking is to strengthen the cornea and slow or stop further progression.

It is important to understand that cross-linking is generally a treatment for progression rather than a simple way to eliminate the existing refractive error.

4. Intracorneal Ring Segments

In selected patients, small implants called intracorneal ring segments (ICRS) may be placed within the cornea.

They can help:

• Regularise corneal shape
• Improve vision
• Make contact lens fitting easier in selected cases

They are not suitable for everyone.

5. Corneal Transplantation

Advanced keratoconus may occasionally cause significant corneal scarring or severe visual impairment that cannot be managed effectively with other treatments.

In such cases, a corneal transplant may be considered.

Depending on the condition of the cornea, procedures can include:

• Deep anterior lamellar keratoplasty (DALK)
• Penetrating keratoplasty (PK)

These procedures replace some or all of the damaged corneal tissue.

Can LASIK Treat Keratoconus?

LASIK is generally not recommended for people with established keratoconus.

LASIK removes corneal tissue to reshape the cornea. Because keratoconus already involves a structurally weakened cornea, removing additional tissue may increase the risk of further weakening.

Anyone considering laser vision correction should undergo detailed corneal mapping and screening before treatment.

Can Keratoconus Be Cured?

There is currently no simple medication or treatment that permanently reverses the underlying corneal shape changes caused by keratoconus.

However, modern treatment can often control progression and significantly improve functional vision.

For example:

• Glasses may help in early disease.
• Contact lenses can improve optical clarity.
• Cross-linking can slow or stop progression in appropriate patients.
• Corneal surgery can help selected patients with advanced disease.

Early diagnosis gives patients more treatment options.

Can You Prevent Keratoconus?

There is no guaranteed way to prevent keratoconus because genetics and other biological factors may play a role.

However, you can take steps to protect your corneas.

Avoid Eye Rubbing

Try not to rub your eyes, particularly if they are itchy.

Treat Eye Allergies

If allergies cause persistent itching, speak with an eye care professional about appropriate treatment.

Have Regular Eye Examinations

Regular monitoring is particularly important if you have a family history of keratoconus or progressive changes in your prescription.

Protect Your Eyes

Use appropriate protective eyewear during activities where eye injury is possible.

Keratoconus and Eye Rubbing: Why It Matters

Eye rubbing deserves particular attention.

If your eyes are itchy, rubbing may feel like a quick way to relieve the discomfort. However, repeated vigorous rubbing can place mechanical stress on the cornea.

If you frequently rub your eyes because of allergies or dryness, treating the underlying problem may help you break the habit.

Parents should also discourage children from rubbing their eyes, particularly if they have a family history of keratoconus.

When Should You See an Eye Doctor?

Arrange a comprehensive eye examination if you experience:

• Rapidly changing glasses prescriptions
• Increasing astigmatism
• Persistent blurred vision
• Distorted vision
• Increasing difficulty seeing at night
• Difficulty achieving clear vision with glasses
• Frequent eye rubbing
• A family history of keratoconus

Early assessment is particularly important for children and teenagers with rapidly changing vision.

Frequently Asked Questions

Is keratoconus a serious eye condition?

Keratoconus can progressively affect vision, but early diagnosis and modern treatments can help manage the condition and preserve useful vision.

Can keratoconus make you blind?

Severe keratoconus can cause significant visual impairment, particularly if corneal scarring develops. However, complete blindness is uncommon, and several treatments are available to manage the condition.

Does keratoconus get worse with age?

Keratoconus is often progressive during adolescence and early adulthood. Progression may slow or stabilise later in life, but this varies between individuals. Regular monitoring is important.

Can glasses correct keratoconus?

Glasses can often provide useful vision in early keratoconus. As corneal irregularity increases, specialised contact lenses may provide better visual correction.

Is corneal cross-linking painful?

The experience varies depending on the technique used. Some patients experience discomfort, light sensitivity, or irritation during the early recovery period. Your ophthalmologist will provide appropriate postoperative medication and instructions.

Can I wear contact lenses if I have keratoconus?

Yes. Many people with keratoconus achieve useful vision with specialised contact lenses, including rigid gas-permeable and scleral lenses.

Conclusion

Keratoconus is a progressive condition in which the cornea becomes thinner and more irregular, affecting the quality of vision. It often develops during adolescence or early adulthood and may initially look like ordinary short-sightedness or astigmatism.

Frequent changes in prescription, increasing astigmatism, distorted vision, difficulty seeing at night, or an inability to achieve clear vision with glasses can all warrant further assessment.

Modern diagnostic techniques such as corneal topography and tomography allow ophthalmologists to identify keratoconus and monitor changes over time. Treatments ranging from glasses and specialised contact lenses to corneal cross-linking and corneal surgery can help manage the condition.

If you or your child has progressive changes in vision, particularly alongside frequent eye rubbing or a family history of keratoconus, a comprehensive corneal assessment can help determine the cause and the most appropriate treatment approach.