Astigmatism

One of the most commonly misunderstood eye problems is that of astigmatism. The main symptom of the disorder is that of blurred vision at varying distances and, left untreated, it can cause a number of additional problems such as headaches and eye strain. This is caused by the shape of the cornea and the way that it directs light onto the retina. A normal eye that does not require corrective glasses or surgery is typically shaped like a perfect sphere, or a football. With astigmatism, the three dimensional form of the eye is more oval shaped like a rugby ball and this makes the condition more difficult to treat than straightforward near or far sightedness. However, in some instances, astigmatism can also be caused by the shape of the lens and in these cases the condition is referred to as lenticular astigmatism. Unlike many age related eye problems, astigmatism typically occurs early on in life and it is important to address the issue as soon as it is identified as it can have an undesirable effect on a young person’s life such as having a negative impact on education and personal development.

Different Classifications of Astigmatism

There are many different types of astigmatism with the most common manifestations being classified as myopic astigmatism, hyperopic astigmatism and mixed astigmatism. In the case of myopic astigmatism, the irregular shape of the cornea is responsible for nearsightedness, whereas with hyperopic astigmatism the patient will suffer the effects of farsightedness. With mixed astigmatism, the condition causes vision difficulties in terms of focusing on objects which are both too close and too far away. If you are suffering from astigmatism then an ophthalmologist should be able to accurately identify the type and severity of the complaint with a routine eye examination known as a retinoscopy. This involves a qualified eye doctor shining a light directly into each affected eye whilst placing a series of curved lenses between the light and the front of the eye in order to estimate the refractive error. The procedure is either done manually or by using a computer controlled machine. Once the condition has been accurately assessed, you will be given an eyeglass prescription in order to correct problem.

Available Treatment Options

The main types of vision correction available for those suffering from astigmatism are contact lenses, prescription glasses and refractive surgery. In the case of nearsightedness (myopia) and farsightedness (hyperopia), the prescription is calculated using a spherical lens power index. However, with myopic or hyperopic astigmatism an additional index is required. This is known as the cylinder lens power and it is necessary because of the additional level of correction that astigmatism patients need. Although glasses and contact lenses can compensate for astigmatism, they cannot cure condition. This is where laser eye surgery has a distinct advantage as it can eliminate the need of prescription glasses entirely by means of dealing with the problem directly through altering the actual shape of the cornea and reducing the refractive error to an absolute minimum. If the patient is under the age of twenty one then they will usually require eye glasses as refractive surgery is only advisable for young adults whose eyes are fully developed. Additionally, refractive surgery types such as laser vision correction (LASIK or LASEK) and photorefractive keratotomy (PRK) are not recommended for those with an eyeglasses prescription that is unstable and changes at regular intervals.