Astigmatism — Causes, Symptoms and Treatment Options
Astigmatism can cause blurred, distorted or shadowed vision at both distance and near. Some people notice difficulty reading road signs or increased glare at night, while others experience eye strain, headaches or reduced visual clarity that glasses only partially improve.
In children, significant astigmatism may interfere with visual development and contribute to amblyopia (“lazy eye”). In adults, astigmatism can affect reading comfort, driving, sport and overall quality of vision.
Modern treatment options range from glasses and contact lenses through to laser eye surgery, implantable collamer lenses (ICL) and astigmatism correction during lens replacement surgery or cataract surgery. In some cases, astigmatism is due to corneal injury or disease such as keratoconus. Dr Daya Sharma specialises in surgical treatments for these more complex cases.
What Is Astigmatism?
Astigmatism is a type of refractive error which causes distorted images which are elongated in one direction. Unlike simple myopia (shortsightedness), with astigmatism, there is no clear point of focus at any distance from the eye. Astigmatism usually is produced when the cornea is shaped more like a rugby ball than a soccer ball. Astigmatism can arise from the lens of the eye.
Instead of focusing light to a single sharp point, the eye focuses light typically onto 2 planes. This results in blurred, stretched, shadowed or distorted vision.
Many patients describe astigmatism as:
- blurred vision that is difficult to sharpen completely
- doubled or “ghosted” edges around letters
- glare around lights at night
- difficulty seeing road signs clearly
- visual fatigue after prolonged concentration
Astigmatism typically affects distance and near vision.
Some people have only mild astigmatism with few symptoms. Others develop significant visual blur that interferes with daily activities.
There are several forms of astigmatism.
Regular Astigmatism
Regular astigmatism occurs when the eye has two principal focusing meridians positioned at right angles to each other. This is the most common form and is often successfully corrected with glasses, soft contact lenses, laser vision correction or lens based surgery.
Irregular Astigmatism
Irregular astigmatism occurs when the surface of the cornea becomes uneven or asymmetrical.
This may occur with:
- keratoconus
- corneal scarring
- previous eye surgery
- pterygium
- corneal trauma
Irregular astigmatism is more difficult to correct with glasses alone, because vision is often suboptimal with the best correction with glasses. Irregular astigmatism may require specialised hard contact lenses or surgical treatment.
Corneal vs Lenticular Astigmatism
Most astigmatism originates from the cornea. However, the natural lens inside the eye can also contribute to astigmatism.
This becomes increasingly relevant during cataract surgery planning, where both corneal and lenticular astigmatism influence visual outcomes. Furthermore, cataract surgery removes any astigmatism that is induced by the lens. Hence, part of cataract surgery planning involved calculating the component of the astigmatism that is induced by the cornea using corneal imaging.
What Symptoms Can Astigmatism Cause?
The symptoms of astigmatism vary depending on the amount of refractive error, pupil size, lighting conditions and the overall health of the eye.
Some patients notice symptoms only at night. Others struggle throughout the day despite wearing glasses.
Common symptoms include:
- blurred vision
- distorted vision
- shadowing or ghosting around letters
- glare from headlights
- halos around lights
- headaches
- eye strain
- fatigue while reading
- fluctuating visual clarity
- difficulty focusing during prolonged screen use
Astigmatism may also reduce contrast sensitivity. This means some patients can technically read an eye chart reasonably well while still feeling that their vision lacks sharpness or clarity in real-world situations.
Many patients particularly notice problems:
- driving at night
- reading subtitles
- using computers for prolonged periods
- watching presentations or lectures
- participating in sport
- tracking moving objects
Symptoms may worsen if another condition is also present, such as:
- dry eye disease
- cataract
- keratoconus
- ocular surface disease
Astigmatism in Children and Visual Development causing Amblyopia
Vision develops rapidly during childhood. During this period, the brain learns how to interpret visual information from both eyes. If the visual connections between the eye and brain do not form this is called amblyopia.
If significant astigmatism causes persistent blur during this critical developmental period, the visual pathways may not develop normally.
Children do not complain about blurred vision, as they don’t know what other children can see. Furthermore, if one eye sees well they don’t usually realise that one eye is doing all the work.
Others may experience:
- reading difficulties
- poor concentration
- eye rubbing
- headaches
- squinting
- reduced academic performance
- reduced depth perception
Children with high astigmatism sometimes assume their vision is normal because they have never experienced clearer vision.
Early detection is important because treatment during the period of plasticity, which is the first 7 years of life is when these connections can be made most effectively.
Astigmatism may occur:
- in one eye
- in both eyes
- or unequally between the two eyes
Unequal blur between the eyes may significantly increase the risk of amblyopia.
Can Astigmatism Cause Amblyopia?
Yes. Significant or unequal astigmatism during childhood can interfere with normal visual development and contribute to amblyopia.
Amblyopia, commonly called “lazy eye,” occurs when the brain does not develop normal visual processing from one or both eyes during childhood.
When astigmatism causes persistent blur, the brain may begin to suppress the unclear image. Over time, this can lead to permanently reduced vision if not treated early enough.
Astigmatism-related amblyopia may occur:
- in one eye
- or in both eyes
This is sometimes referred to as meridional amblyopia.
The risk is generally higher when:
- astigmatism is large
- the blur is asymmetrical
- treatment is delayed
- glasses are not worn consistently
Treatment may include:
- glasses
- patching
- atropine therapy
- monitoring visual development
- management of associated eye conditions
The earlier amblyopia is identified, the better the potential for visual improvement.
How Astigmatism Can Affect Everyday Vision
Astigmatism affects more than just the ability to read an eye chart.
Even relatively small amounts of astigmatism may reduce visual quality in real-world situations, particularly in low light or visually demanding environments.
Some patients report:
- difficulty driving at night
- glare from headlights
- reduced confidence in rain or poor weather
- visual fatigue after long workdays
- trouble reading fine print
- fluctuating focus during prolonged screen use
Others notice reduced visual performance during:
The effect often becomes more noticeable as pupil size increases in dim lighting conditions.
Many patients can function reasonably well during the day yet still feel their vision is not “crisp” or comfortable.
Visual quality depends on more than standard visual acuity alone. Corneal shape, higher-order aberrations, ocular surface quality and pupil size may all contribute to symptoms.
How Is Astigmatism Treated?
Treatment depends on:
- the amount of astigmatism
- patient age
- visual needs
- corneal shape
- eye health
- lifestyle goals
Some patients only require observation or minor glasses correction. Others may benefit from more advanced treatment approaches.
Glasses for Astigmatism
Glasses remain one of the most common treatments for astigmatism.
Special cylindrical lenses compensate for the uneven focusing power within the eye and can significantly improve vision in many patients.
However, some patients continue to notice:
- distortion
- reduced peripheral clarity
- magnification effects
- night glare
- visual fatigue
This may become more noticeable with higher prescriptions.
Contact Lenses for Astigmatism
Toric contact lenses may provide sharper vision for some patients because they move with the eye and reduce some of the optical effects associated with glasses.
However, comfort and stability may vary.
Some patients experience:
- dryness
- lens rotation
- fluctuating clarity
- irritation during prolonged wear
Specialised rigid or scleral lenses may sometimes help patients with irregular astigmatism.
Laser Eye Surgery for Astigmatism
Laser eye surgery may reduce or eliminate astigmatism in appropriately selected patients.
Modern refractive procedures can reshape the cornea to improve focusing accuracy and visual quality.
Different techniques may be considered depending on:
- corneal thickness
- corneal shape
- prescription
- ocular surface health
- age
- occupation
- visual goals
Procedures may include:
- LASIK
- SMILE
- PRK
- TransPRK
- topography-guided treatment
- wavefront-guided treatment
The goal is not simply to reduce glasses dependence, but also to improve the overall quality of vision where possible.
A detailed assessment is important because not every patient is an appropriate candidate for laser vision correction. Refractive surgery, which includes laser vision correction, covers a number of different types of surgery. Suitability varies depending on the measurements of the eye, the degree of astigmatism, and patient factors. If you are considering your suitability for refractive surgery, take the online suitability test, or make an appointment to undertake a complimentary refractive surgery screening assessment.
Cataract Surgery and Astigmatism Correction
Cataract surgery may also provide an opportunity to reduce astigmatism.
During cataract surgery, the natural lens of the eye is replaced with an artificial intraocular lens. Astigmatism can often be addressed at the same time using:
- toric intraocular lenses
- limbal relaxing incisions
- laser-assisted techniques
Correcting astigmatism during cataract surgery may improve:
- distance vision
- reading vision
- visual sharpness
- night vision
- overall visual quality
Residual astigmatism after cataract surgery may still affect visual outcomes, particularly in patients seeking greater spectacle independence.
Careful measurements before surgery are important because corneal shape, ocular surface quality and pupil characteristics can all influence planning accuracy.
When Should You See an Ophthalmologist for Astigmatism?
A detailed eye examination may be worthwhile if you experience:
- blurred vision, especially if worsening
- headaches or eye strain
- difficulty driving at night
- reduced vision despite glasses
- fluctuating visual quality
- significant astigmatism in childhood
- concerns regarding amblyopia
- interest in laser eye surgery
- cataract-related visual changes
Children with significant astigmatism should generally undergo appropriate assessment because untreated blur during visual development may affect long-term vision.
Adults considering surgical correction benefit from detailed corneal imaging and refractive assessment to determine suitability and discuss realistic expectations.
Some patients only require updated glasses. Others may benefit from more advanced treatment options including laser vision correction or cataract surgery.
A comprehensive assessment helps determine the most appropriate approach for your eyes and visual goals.
FAQ SECTION
Can astigmatism worsen with age?
Yes. Astigmatism may change gradually over time due to changes in the cornea, natural lens and ocular surface. Cataract development may also alter astigmatism.
Can laser eye surgery correct astigmatism?
Yes. SMILE Pro, LASIK and PRK can all correct regular astigmatism in suitable candidates following detailed assessment. Dr Daya Sharma also specialises in laser vision correction techniques to correct irregular astigmatism, such as topography-guided PRK and LASIK.
Can cataract surgery correct astigmatism?
Yes. Astigmatism is routinely corrected during cataract surgery using toric intraocular lenses or other surgical techniques.
Can children outgrow astigmatism?
Small amounts of astigmatism may change during childhood. However, significant astigmatism often requires monitoring and sometimes treatment to support normal visual development.
Does astigmatism cause headaches?
It can. Some patients develop headaches or eye strain from prolonged focusing effort, particularly during reading or screen use.
What does astigmatism look like at night?
Many patients describe:
- glare
- halos
- starbursts
- smeared lights
- shadowing around headlights
- reduced sharpness in dim lighting conditions.
Book an Astigmatism consultation
Eye & Laser Surgeons — Bondi Junction & Miranda
Bondi Junction: (02) 9387 5300
Miranda: (02) 9531 5300
Email: reception@eyeandlaser.com.au
