Astigmatism

The British Contact Lens Association (BCLA) defines astigmatism as a ‘focusing disorder of the eye that distorts vision’. If not corrected in time, the quality of vision will get worse.

What is Astigmatism?

Astigmatism is one of the most common refractive errors that affect vision. It is an eye condition caused by an irregular curvature of the cornea, lens, or both. Alongside myopia and presbyopia, it is one of the most common types of refractive errors.

According to the Moorfield Eye Hospital, “People with astigmatism will usually also be short or long sighted”.

Astigmatism explained by Feel Good Contacts’ Contact Lens Optician

Types of astigmatism

Tina Patel, Contact Lens Optician at Feel Good Contacts’ explains astigmatism as…

• Corneal: the cornea is not spherical
• Lenticular: the lens is affected rather than the cornea

Astigmatism can also be described as regular or irregular.

• Regular astigmatism is more common. It occurs when the two curves are perpendicular to each other.
• Irregular astigmatism is less common. In this the curves are not perpendicular to one another and can be a result of an eye injury or keratoconus.

Causes of astigmatism

Astigmatism is caused by an irregular curve on the eye's front surface (cornea). A ‘normal/ spherical’ eye is round, like a football, whilst an eye with astigmatism has two different curves, similar to a rugby ball.

Astigmatism vs normal vision (spherical eye)

But first, it’s important to understand how the eye works:

1. Light passes through the cornea (the clear front layer of your eye).
2. The cornea focuses the light through the pupil and lens and focusses on the retina (the layer at the back of your eye).
3. The retina converts the light into electrical signals.
4. These signals are then sent to the brain by the optic nerve.
5. The brain converts the received signals into an image that you can see.

If you have astigmatism, the irregularity in the curve changes the way that light refracts onto your retina, resulting in blurry vision at all distances.

The light that enters an astigmatic eye doesn’t focus on the retina, resulting in blurred vision.

Who is at risk for astigmatism?

This condition can affect anyone, at any point of the life. Some people are born with it, while others might develop it later.

You could be at risk of developing this condition if:

• You have a family history of astigmatism
• Your cornea is thin or is thinning over the time
• You have excessive short-sightedness or farsightedness

Symptoms of astigmatism

Symptoms of astigmatism depend on the severity of the condition. Some of the symptoms are listed below:

1. Blurred vision is the most common symptom of this condition, making it harder to see details such as print on the newspaper or a faraway road sign. This pressure of trying to focus can also cause eye fatigue and headaches.
2. Squinting to see clearly can be an indication of astigmatism.
3. You might face difficulty seeing at night, because of seeing glare or halos caused by streetlights and car headlights.
4. Headache or eyestrain - with blurry vision, your eyes will work harder to focus causing eye fatigue and headaches.
5. Too much pressure on the eye can make your eye feel irritated
6. Double vision

Diagnosis and test

An optometrist will be able to diagnose astigmatism through an eye examination. The eye test may include:

1. Visual acuity test: This includes reading letters (or symbols sometimes) off a wall chart at a measured distance.

   

   

2. Phoropter: This is a binocular-like device where you must look through and confirm which letters you can see. This test helps your optician to the work out the prescription.

   

   

3. Autorefractor: This device provides an initial reading of your prescription and can help measure your astigmatism and other refractive errors.

   

   Source: Baytex Opticians

   

   Source: Baytex Opticians

4. Keratometer: This device measures the curvature of your cornea, which is essential for the correct fitting contact lens.

   

   Source: Baytex Opticians

   

   Source: Baytex Opticians

Treatment for astigmatism

The only form of astigmatism treatment is refractive surgery. However, there are other options that can correct your vision. The most common way to correct astigmatism is by wearing corrective contact lenses or prescription glasses. However, depending on how severe your astigmatism is, there are a range of management options available.

Contact Lenses

Contact lenses are an effective way to manage this condition. Your optician will recommend toric lenses that are specifically designed to correct astigmatism.

Prescription Glasses

Glasses are another effective way to correct astigmatism. Your optometrist may recommend a single-vision, bifocal or progressive glasses.

Refractive surgery

Undergoing surgery to correct astigmatism will mostly eliminate the need to wear contact lenses or glasses. However, your doctor will evaluate whether this is a suitable option for you. There are different types of refractive surgery for astigmatism:

• Laser in situ keratomileusis (LASIK)
• Photorefractive keratectomy (PRK)
• Laser-assisted subepithelial keratectomy (LASEK)

Please note: Before opting for any visual correction, its important to consult your optician who will be able to recommend a suitable treatment based on the severity of your condition.

Optician’s recommended contact lenses for astigmatism

Please note that all our contact lenses at Feel Good Contacts are sourced directly from authentic manufacturers, promising you the quality and passing on the savings to you!

Test your vision with our Vision Simulator Test

Want to see how people with astigmatism would see the world? Try our Vision Simulator tool.

What is a bad level of astigmatism?

The term ‘bad level’ of astigmatism is subjective and depends on the severity of this condition. Astigmatism is typically measured in ‘dioptres’ and can be categorised as follows:

• Mild: Less than 1.00 dioptres
• Moderate: 1.00 to 2.00 dioptres
• Severe: 2.00 to 3.00 dioptres
• Extreme: More than 3.00 dioptres

How can I fix my astigmatism naturally?

It is unlikely for astigmatism to get fixed naturally. However it is a good practice to follow eye exercises which could help to keep your eyes healthy.

Can you be short-sighted and have astigmatism at the same time?

Yes, you can be short-sighted and have astigmatism at the same time. If you’re unsure, you should get your eyes tested. Your optician will be able to give you an up-to-date prescription and recommend contact lenses and glasses accordingly. Read our article to know more.

Sources:

https://my.clevelandclinic.org/health/diseases/8576-astigmatism
https://www.healthline.com/health/astigmatism
https://www.nhs.uk/conditions/astigmatism/
https://www.moorfields.nhs.uk/condition/astigmatism
https://www.bcla.org.uk/Public/Public/Consumer/Astigmatism_and_contact_lenses.aspx
https://www.mayoclinic.org/diseases-conditions/astigmatism/symptoms-causes/syc-20353835
https://www.aao.org/eye-health/diseases/what-is-astigmatism