Between 2 and 4 diopters is moderate astigmatism, and 4 or more diopters is considered significant or “bad” astigmatism.
Mild Astigmatism <1.00 diopters. Moderate Astigmatism 1.00 to 2.00 diopters. High Astigmatism 2.00 to 4.00 diopters.
The astigmatism severity scale ranges from mild (less than 1.00 diopter) to extreme (more than 3.00 diopters).
An axis of 180 degrees means that the astigmatism is horizontal. Hence, the patient is moderately near-sighted with a slight degree of horizontal astigmatism.
The amount of astigmatism (visual distortion) that is caused by an irregularly shaped cornea. If this box is empty, it means that there is no astigmatism and your eyes are perfectly spherical. A low number like 0.25 means your eyes are not quite round and a higher number like 3.00 means your eyes are quite oval.
What Level of Astigmatism Requires Glasses? You'll likely need glasses if your astigmatism has a strength of 1.0 or more. But even if your astigmatism needs less than 1.0 diopters of correction, it doesn't mean you won't need glasses.
If there is only a small amount of astigmatism -0.25 or -0.50 then you might not need this corrected, especially if it is fairly straight (near to 90 axis or 180 axis on your prescription).
Most people have between 0.5 to 0.75 diopters of astigmatism. People with a measurement of 1.5 or more typically need contacts or eyeglasses to have clear vision.
Small amounts of astigmatism, up to 0.50 Diopter, probably will not bother you during your normal activities. Vision becomes noticeably blurry with 1.00 Diopter of astigmatism or more.
Astigmatism has a maximum power in a certain meridian or direction, which we call axis. Axis run from 1 to 180 and then starts all over again. Axis 0 is the same as axis 180 and we never write axis 0, it's always 180.
Prescription eyeglasses for astigmatism are generally considered optional if your uncorrected vision (meaning your vision without corrective lenses) is 20/40 or better. However, even if your vision is 20/40 or better, you might still end up with eye strain or headaches if you don't wear glasses.
Astigmatism frequently worsens with age. Your cornea can become more irregular due to pressure from your eyelids as they lose muscle tone. Astigmatism generally stays stable until your turn 50. After then, your lens curvature progressively worsens each decade.
The ultra-precise lasers used for LASIK surgery can be programmed to reshape the cornea so the front surface of the eye is more symmetrical, thereby eliminating vision problems caused by astigmatism. Most of the time astigmatism can be fully corrected with a single LASIK procedure.
Glasses. One of the most common ways to fix an astigmatism, glasses contain a cylindrical lens that compensates for the uneven curves in your cornea or lens. People with a severe astigmatism may be better suited for glasses instead of contacts.
Your AXIS number will be a whole number between 1 and 180. For example, if your AXIS number is 180 then your astigmatism is corrected by placing the cylinder horizontally on your lens. Many people's prescriptions fall in between these right angles, but most commonly near 180 or 90 degrees.
It has long been considered very treatable, like other refractive errors. Most people with astigmatism have normal lives with the help of glasses or contact lenses. There are two forms of laser eye surgery that can effectively cure astigmatism by reshaping the cornea. These are LASIK and PRK.
The second number (cylinder) indicates the amount of astigmatism you have. The further the number is from zero, the more pronounced the astigmatism. A value up to 2.50 is considered moderate; anything above 2.50 may be considered severe.
Glasses or soft contacts can usually correct regular astigmatism to 20/20, but if it is a high degree of astigmatism, the eye may not be correctable to 20/20.
Between . 75 and 2 diopters is considered mild astigmatism. Between 2 and 4 diopters is moderate astigmatism, and 4 or more diopters is considered significant or “bad” astigmatism. Generally, eyes with 1.5 diopters of astigmatism or more require correction.
Before we jump into what each section means, as a general rule, the higher the numbers on your prescription, the worse your eyesight is and the stronger your prescription will be to provide the necessary correction. Mild: -0.50 to -3. Moderate: -3.25 to -5.00. High: -5.25 to -10.
Most people have a mild prescription, between 0.5 to 0.75 D. They may not really notice it in their daily lives. People with a measurement of more than . 75 D may need contacts or eyeglasses to correct their vision to see clearly.
Cylinder (CYL)
You will observe (-) CYL values for short-sighted astigmatism e.g. -0.50 or -1.25. These lenses will be cylindrical on the inside surface (closest to your eye). You will see (+) CYL values for far-sighted astigmatism e.g. +0.75 or +1.25.
Glasses or contacts can correct almost all cases of astigmatism. But if you have only a slight astigmatism and no other vision problems, you may not need them. If you have a common level of astigmatism, you'll probably have corrective lenses, like glasses or contacts, or surgery.
The result is blurry vision. People with astigmatism may experience mild to severe distorted vision, depending on the degree of astigmatism. While myopia (nearsightedness) makes far-away objects blurry and hyperopia (farsightedness) makes close-up objects blurry, astigmatism makes things blurry at every distance.