What is the normal range for astigmatism?

75 diopters of astigmatism, and this is considered normal and will likely not require correction. 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.

What chart is used for astigmatism?

The Snellen eye chart is the eye testing chart used by eye care professionals to measure visual acuity, or how well a patient can see without glasses or contacts. Dr. Hermann Snellen developed the eye chart in 1862.

What is my vision if I have astigmatism?

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.

What’s considered a bad astigmatism?

Moderate Astigmatism 1.00 to 2.00 diopters. High Astigmatism 2.00 to 4.00 diopters. Extreme Astigmatism > 4.00 diopters.

What does Snellen 6 12 mean?

If this is the smallest line a person can read, the person’s acuity is “6/12” (“20/40”), meaning that this person needs to approach to a distance of 6 metres (20 ft) to read letters that a person with normal acuity could read at 12 metres (39 ft).

Is 175 astigmatism bad?

The last and 3rd number (180 and 175) is the axis, or the direction of your astigmatism. An axis of 180 degrees, for example, means the astigmatism is horizontal. Therefore, this prescription means that the patient is moderately nearsighted, with a moderate degree of astigmatism in a horizontal direction.

What is considered mild astigmatism?

The table below shows the categories of severity for astigmatism: Mild Astigmatism <1.00 diopters. Moderate Astigmatism 1.00 to 2.00 diopters. High Astigmatism 2.00 to 4.00 diopters.