What is it?
Astigmatism comes about when the front portion of the eye, technically referred to as the cornea, isn’t a uniform radial apple-shaped shape. Instead, its mold is quite like that of the back of a spoon - longer in one direction than another. Due to the fact that the cornea is an irregular shape, the eye can’t focus light passing through it sharply on to the back of the eye or retina. So vision is obscured at all distances.
What causes it?
As the eye forms in the womb, several components define the shape of it, including familial genetic factors and nurture. It turns out that these factors can result in an jagged curve of the cornea, although the exact cause isn’t known.
Who’s affected?
Actually most of us have an astigmatism - but generally it is very mild
Astigmatism is common and is commonly present when a person is born. Most people have a mild astigmatism - it’s uncommon for the cornea to have developed in a perfectly symmetrical manner. But in mild cases, the eye can adjust to focus light adequately.
In many instances of astigmatism the person also has accompanied optical troubles like short-sightedness or long-sightedness. Two-thirds of people with short-sightedness also have significant astigmatism.
What are the symptoms?
In severe astigmatism, vision is blurred or distorted whether the person is reading close up or looking further into the distance.
In milder cases the individual may complain their vision is obscured at certain distances, that they’ve tired or dry eyes, that it’s a struggle to focus or read, or that they’ve headaches, especially when trying to focus.
How is it diagnosed?
Astigmatism should be diagnosed by a certified optometrist, ophthalmic surgeon or eye specialist. A full optometric examination should be done to assess the degree and extent of the problem.
Tiny children, who mightn’t be able to respond to the optometrist’s queries about what they can see, can be assessed using a test called retinoscopy that involves reflected light.
What’s the treatment?
Most of the time, you can adequately deal with an astigmatism by using properly prescribed eyeglasses or contact lenses.
Milder astigmatism may not need treatment unless the person is doing a job that puts intensive demands on the eyes, for example, computer work.
In some cases, astigmatism can be corrected by an operation called refractive surgery, which reshapes the cornea.
Some may choose laser surgery. You should discuss the benefits and risks of this treatment with your surgeon before you go decide whether to have it.
