26. July 2013 12:38
Astigmatism is a refractive error that is not as common as myopia, but it affects a large number of patients who need special types of contact lenses or glasses. It occurs when the cornea is not spherical, but toric, as a result of which the image on the retina is unclear.
The condition is fairly easy to correct with glasses, but it used to cause some problems when contact lenses were used. This was associated with difficulties achieving appropriate stability (important because of the irregularity of the astigmatic cornea).
Fortunately, modern designs have eliminated the issue and, wearing contacts, astigmatic patients can enjoy the same acuity of vision as myopes. In addition, astigmatics have a number of excellent options to choose from – including various types of materials (rigid gas permeable, hydrogel, silicone hydrogel ones), modalities (from daily disposable contact lenses to monthly ones) and sizes (standard, mini-scleral, scleral).
Patients with common types of astigmatism can be fitted with contact lenses immediately. Those with more complicated cases might have to wait for lenses adjusted to their refractive errors, but the ultimate results are virtually identical.