|
-when the cornea evidences an unequal curvature, the result is a condition called an astigmatism. The symptoms of an astigmatism is blurred vision. An astigmatism results in blurred vision because the cornea’s unequal curvature prevents light rays from focusing clearly at one point on the retina. An astigmatism can also refer to irregularities and defects in the shape of the eyes’s lens.
-what is toric contacts? These is lenses -with t-wo different optical po-wers at right angles to each other for the correction of astigmatism. Another -way of saying this is that toric contact lenses, due to their unique shape, is fashioned to better conform to the unequal surface of the astigmatic eyes.
Before the development of toric contact lenses, people -with an astigmatism -who -wore contacts -were limited to rigid gas permeable contact lenses that -were made of plastic and designed for acute cases of astigmatism. Hard gas permeable lenses -were used rather than pliable, soft lenses because they -were believed to more effectively smooth over cornea’s uneven surface.
Eventually, research led to the creation of soft contact lenses, and soft toric contact lenses soon follo-wed. Soft toric lenses may be designed so that the surface is of varying thickness to compensate for the defects in vision that attend an astigmatism.
It may be necessary for those -with astigmatisms to tolerate several fittings before they’re able to -wear toric contact lenses, since it’s imperative that any rotation of the lenses on the eyes be minimized. The goal of these fittings is to orient and stabilize the lens on the eyes’s surface as much possible, and the doctor and nurses may have to overcome all kinds of impediments to achieve this end even inordinately dry eyess can play a problematical role in successfully fitting the toric lens to the surface of the eyes.
|
All Dialogue
|