Astigmatism: symptoms, causes, cylindrical number and treatment

By the team at Babar Homeopathic Clinic & EyeBar OpticalPublished 3 October 20266 min read

What is astigmatism?

In a normal eye the cornea, the clear front window, is curved evenly like a cricket ball. Light entering the eye comes to a single sharp point on the retina. In astigmatism the cornea, or sometimes the lens inside the eye, is curved more steeply in one direction, like the back of a spoon. Light then focuses at two different points, and the image is never fully sharp.

Almost everyone has a small amount. It only needs correcting when it blurs vision or causes strain. The American Academy of Ophthalmology describes it as one of the most common vision problems, alongside short sight and long sight.

What does someone with astigmatism see?

• Blurred or slightly doubled edges on letters, at distance and near
• Lines in one direction sharper than lines in another
• Street lights and headlights stretched into streaks at night
• Similar letters confused, such as H and N, or 8 and 0

You can check this yourself in a minute with the dial below. If some groups of lines look darker than others, astigmatism is likely.

Symptoms of astigmatism

• Blurred or distorted vision at all distances
• Eye strain and tired eyes, worse by evening
• Headaches, especially after reading or screen use
• Squinting or half-closing the eyes to see clearly
• Difficulty driving at night

Children rarely complain. Watch for squinting, tilting the head, sitting close to the TV and poor copying from the school board. See how to check eyesight at home.

What causes astigmatism?

Most astigmatism is present from birth and runs in families. It is the shape you were born with. Less common causes are an eye injury, eye surgery, and keratoconus, a condition in which the cornea thins and bulges forward during the teenage years. Reading in dim light, sitting close to the TV and using a phone do not cause astigmatism.

Types of astigmatism

What is a cylindrical number?

On a glasses prescription astigmatism is written in two columns. CYL (cylinder) is the amount, such as −0.75 or −1.50. Axis is the direction, a number from 0 to 180. An axis of 180 lies horizontally and 90 lies vertically. The SPH column is your ordinary short-sight or long-sight number.

Every term on the slip is explained in how to read your eye prescription.

How is astigmatism tested?

It is measured during an ordinary eye test. A computerized machine, the autorefractor, reads the curve of the eye and gives a starting cylinder and axis in seconds. The reading is then refined with trial lenses while you look at the chart, because a small error in the axis blurs vision. If keratoconus is suspected, an eye specialist maps the cornea with a topography scan.

At EyeBar Optical in Kangan Pur the computerized eye test is totally free.

How is astigmatism treated?

• Glasses. The simplest and safest correction. The lens has a cylinder ground in at your axis. An anti-glare coating helps with night-time streaks. See lens types.
• Toric contact lenses. Soft lenses with a cylinder, weighted so they sit at the right angle. See contact lenses.
• Laser surgery. LASIK and similar procedures reshape the cornea in adults whose number has been stable for at least a year. It is done by an eye surgeon after scans.
• Special lenses. Irregular astigmatism from keratoconus may need rigid or scleral contact lenses fitted at an eye hospital.

Eye exercises, eye drops and diet do not remove astigmatism, because the cause is the shape of the eye.

Is astigmatism a big problem?

For most people, no. It is a focusing error that glasses correct fully. It matters more in two situations. In young children, uncorrected high astigmatism can lead to a lazy eye, so children should be tested early. In teenagers, astigmatism that increases quickly can be an early sign of keratoconus and should be seen by an eye specialist. The Mayo Clinic lists these same points.

Does astigmatism get worse?

It usually changes slowly over the years. Rubbing the eyes hard and often is linked with keratoconus, so treat eye allergy and avoid rubbing. Have your eyes tested every one to two years, and every year for children.

Choosing glasses when you have a cylinder

• Have the frame fitted properly. If glasses sit crooked, the axis is wrong and vision blurs.
• Give new glasses a week. Floors may look tilted for a few days while the brain adapts.
• For a high cylinder, choose a smaller frame and a good-quality lens.
• If you want contact lenses, the cylinder power may need converting. Try the glasses to contact lens calculator.

Nazar ka check-up totally free kia jata hai. Computerized eye testing at EyeBar Optical, Kangan Pur is totally free.

Questions

Sources and further reading

• American Academy of Ophthalmology: astigmatism
• Mayo Clinic: astigmatism, symptoms and causes
• Cleveland Clinic: astigmatism

Written by the team at Babar Homeopathic Clinic & EyeBar Optical, Kangan Pur. Last updated 3 October 2026. This guide is general information and does not replace an examination. See our medical disclaimer.