eye-vision
What Is Astigmatism and Can It Be Fixed?
Astigmatism is a common, usually mild condition where the cornea or lens is slightly irregularly curved — more oval than round — causing blur or distortion at near and far distances. Most astigmatism is present from birth and is not caused by lifestyle habits. It is correctable with glasses, contact lenses, or in many cases laser surgery (LASIK, PRK, or SMILE).
What causes astigmatism?
The eye focuses light best when the front surface — the cornea — is evenly curved in all directions, like a smooth sphere. Astigmatism occurs when the cornea (or sometimes the eye's internal lens) is shaped more like the back of a spoon: curved more steeply in one direction than the other. This causes light entering the eye to be refracted (bent) unevenly, so it converges at two different focal points instead of one clean spot on the retina. 1Ref 1Jacobs DS, Afshari NA, Bishop RJ, Keenan JD, Lee J, Shen TT, Vitale S; American Academy of Ophthalmology Preferred Practice Pattern Refractive Management/Intervention Panel (2023).Refractive Errors Preferred Practice Pattern.Astigmatism definition, causes, correction modalities (glasses, toric contacts, LASIK/PRK, implantable lenses, orthokeratology), and diagnostic approach including corneal topography
Types by location: - Corneal astigmatism — the uneven curvature is in the cornea. The most common type. - Lenticular astigmatism — the uneven curvature is in the eye's internal lens.
Types by orientation of the steepest curve: - With-the-rule — the steepest curve runs vertically - Against-the-rule — the steepest curve runs horizontally - Oblique — the steep curve is at an angle
Most astigmatism is present from birth and tends to run in families. It is not caused by reading in low light, sitting too close to screens, or any behavior. 2Ref 2National Eye Institute (2025).Types of Refractive Errors.Astigmatism as a common refractive error; congenital nature; symptom profile including blur at all distances; frequent co-occurrence with myopia or hyperopia
What does astigmatism feel like — what are the symptoms?
Symptoms vary with the degree of astigmatism. Very mild astigmatism may cause no noticeable symptoms. More significant cases typically cause: 1Ref 1Jacobs DS, Afshari NA, Bishop RJ, Keenan JD, Lee J, Shen TT, Vitale S; American Academy of Ophthalmology Preferred Practice Pattern Refractive Management/Intervention Panel (2023).Refractive Errors Preferred Practice Pattern.Astigmatism definition, causes, correction modalities (glasses, toric contacts, LASIK/PRK, implantable lenses, orthokeratology), and diagnostic approach including corneal topography
- Blurry or distorted vision at all distances (not just far or near)
- Difficulty reading fine print or letters that seem to 'smear' in one direction
- Eye strain, especially after extended reading or screen use
- Squinting to see more clearly
- Headaches, particularly frontal headaches after visually demanding tasks
- Glare or halos around lights at night
In children, undiagnosed astigmatism can interfere with reading development and learning. Because children often do not know their vision differs from normal, routine screening and comprehensive pediatric eye evaluations are important. 3Ref 3Hutchinson AK, Morse CL, Hercinovic A, Cruz OA, Sprunger DT, Repka MX, Lambert SR, Wallace DK; American Academy of Ophthalmology Preferred Practice Pattern Pediatric Ophthalmology/Strabismus Panel (2023).Pediatric Eye Evaluations Preferred Practice Pattern.Importance of detecting astigmatism in children through routine screening; risk of amblyopia and developmental impact with uncorrected refractive error
How is astigmatism measured and diagnosed?
An optometrist or ophthalmologist diagnoses astigmatism during a routine eye exam using:
- Visual acuity testing — how well you read the chart at different distances
- Refraction — the phoropter test where you compare lens options ('better with 1 or 2?')
- Keratometry — measurement of the corneal curvature
- Corneal topography — a detailed map of the entire corneal surface, used when high or irregular astigmatism is suspected 1Ref 1Jacobs DS, Afshari NA, Bishop RJ, Keenan JD, Lee J, Shen TT, Vitale S; American Academy of Ophthalmology Preferred Practice Pattern Refractive Management/Intervention Panel (2023).Refractive Errors Preferred Practice Pattern.Astigmatism definition, causes, correction modalities (glasses, toric contacts, LASIK/PRK, implantable lenses, orthokeratology), and diagnostic approach including corneal topography
The prescription result lists your astigmatism as a cylinder (CYL) power and an axis in degrees, which together describe the amount and orientation of the correction needed.
What are the correction options for astigmatism?
Glasses The most straightforward correction. Lenses are ground with a cylindrical component that compensates for the uneven curvature. Most people with astigmatism are fully correctable with glasses.
Contact lenses Toric soft contact lenses are designed specifically for astigmatism, with stabilization features that keep the corrective axis aligned on your eye. Rigid gas-permeable (RGP) and scleral lenses can also correct astigmatism, often providing sharper vision for higher or irregular prescriptions. Fitting is more involved than for standard contacts. 1Ref 1Jacobs DS, Afshari NA, Bishop RJ, Keenan JD, Lee J, Shen TT, Vitale S; American Academy of Ophthalmology Preferred Practice Pattern Refractive Management/Intervention Panel (2023).Refractive Errors Preferred Practice Pattern.Astigmatism definition, causes, correction modalities (glasses, toric contacts, LASIK/PRK, implantable lenses, orthokeratology), and diagnostic approach including corneal topography
Laser refractive surgery (LASIK, PRK, SMILE) Laser procedures reshape the corneal tissue to eliminate or significantly reduce the refractive error. These procedures are effective for many types and degrees of astigmatism and can reduce or eliminate the need for glasses or contacts. Not everyone is a candidate — corneal thickness, degree of astigmatism, and corneal regularity all matter. An ophthalmologist performs a detailed evaluation before recommending surgery. 1Ref 1Jacobs DS, Afshari NA, Bishop RJ, Keenan JD, Lee J, Shen TT, Vitale S; American Academy of Ophthalmology Preferred Practice Pattern Refractive Management/Intervention Panel (2023).Refractive Errors Preferred Practice Pattern.Astigmatism definition, causes, correction modalities (glasses, toric contacts, LASIK/PRK, implantable lenses, orthokeratology), and diagnostic approach including corneal topography
Implantable lenses (ICL / toric IOL) For people who are not laser surgery candidates, implantable collamer lenses or toric intraocular lenses can correct high degrees of astigmatism. These are surgical options discussed with an ophthalmologist.
Orthokeratology (Ortho-K) Specially designed rigid lenses worn overnight that temporarily reshape the cornea, providing clear vision during the day without glasses or contacts. Used especially for myopia control in children and adolescents. 1Ref 1Jacobs DS, Afshari NA, Bishop RJ, Keenan JD, Lee J, Shen TT, Vitale S; American Academy of Ophthalmology Preferred Practice Pattern Refractive Management/Intervention Panel (2023).Refractive Errors Preferred Practice Pattern.Astigmatism definition, causes, correction modalities (glasses, toric contacts, LASIK/PRK, implantable lenses, orthokeratology), and diagnostic approach including corneal topography
Does astigmatism get worse over time?
Mild astigmatism is often stable for years. Prescriptions tend to shift modestly in childhood and early adulthood as the eye grows, then stabilize. 2Ref 2National Eye Institute (2025).Types of Refractive Errors.Astigmatism as a common refractive error; congenital nature; symptom profile including blur at all distances; frequent co-occurrence with myopia or hyperopia A sudden significant increase in astigmatism in an adult can sometimes indicate keratoconus — a progressive thinning and forward bulging of the cornea — which requires early diagnosis and specific management by an ophthalmologist.
Regular eye exams allow any changes to be monitored and prescription updates made before vision is noticeably affected.
Common questions
Is astigmatism the same as being nearsighted or farsighted?
No, though they often occur together. Nearsightedness (myopia) and farsightedness (hyperopia) are caused by the overall length or curvature of the eye affecting one focal plane. Astigmatism is a separate irregularity in curvature that blurs vision at multiple distances simultaneously.
Can astigmatism be fixed permanently?
Laser surgery such as LASIK can permanently reshape the cornea to correct astigmatism in eligible candidates. Glasses and contacts correct it optically but do not change the eye itself. Whether surgery is appropriate depends on your eye anatomy, prescription, and overall eye health.
Is a little astigmatism normal?
Very mild astigmatism is common and may require no correction at all if it causes no symptoms. Whether a prescription is needed depends on whether the astigmatism affects your vision or causes symptoms like headaches or eye strain.
Can children have astigmatism?
Yes, and it is important to detect it early. Uncorrected astigmatism in young children can sometimes contribute to amblyopia (reduced vision in one eye). Pediatric eye screenings and comprehensive exams are important for this reason.
Does reading in the dark cause astigmatism?
No. Astigmatism is a structural characteristic of the eye's shape, not caused by reading habits or lighting conditions.
When to see an eye care provider soon
- —Sudden or rapid worsening of vision — not a gradual change over months
- —Frequent headaches combined with visual disturbance
- —Glare or halos around lights that are significantly impairing night driving
- —Any child who squints persistently, covers one eye, or holds books very close
This article is general patient education about astigmatism. It does not constitute a diagnosis or prescription. Diagnosis and correction options should be discussed with an optometrist or ophthalmologist — the right specialists for refractive eye conditions. Gale can help you prepare for that visit.
References
- 1.Jacobs DS, Afshari NA, Bishop RJ, Keenan JD, Lee J, Shen TT, Vitale S; American Academy of Ophthalmology Preferred Practice Pattern Refractive Management/Intervention Panel (2023). Refractive Errors Preferred Practice Pattern. Ophthalmology. doi:10.1016/j.ophtha.2022.10.031 ✓Astigmatism definition, causes, correction modalities (glasses, toric contacts, LASIK/PRK, implantable lenses, orthokeratology), and diagnostic approach including corneal topography
- 2.National Eye Institute (2025). Types of Refractive Errors. National Eye Institute (NIH). link ✓Astigmatism as a common refractive error; congenital nature; symptom profile including blur at all distances; frequent co-occurrence with myopia or hyperopia
- 3.Hutchinson AK, Morse CL, Hercinovic A, Cruz OA, Sprunger DT, Repka MX, Lambert SR, Wallace DK; American Academy of Ophthalmology Preferred Practice Pattern Pediatric Ophthalmology/Strabismus Panel (2023). Pediatric Eye Evaluations Preferred Practice Pattern. Ophthalmology. doi:10.1016/j.ophtha.2022.10.030 ✓Importance of detecting astigmatism in children through routine screening; risk of amblyopia and developmental impact with uncorrected refractive error
3 sources, numbered by first appearance. General health information, not medical advice — synthetic demonstration content.