We all know what contact lenses are for and what they do, but many who have come across the term Toric contact lenses would be forgiven for wondering what the difference is. Toric lenses came about to fill a gap in the market that could not be filled by regular lenses, as whilst these dealt with ordinary sight problems such as long or short sightedness, they did nothing to help those suffering from astigmatism.
This is a completely different condition that required specialist lenses, and the sufferer’s only choice was to wear glasses to which these lenses were added. Toric lenses put an end to this and enabled those with astigmatism to finally throw their glasses to one side and join the ranks of the contact lens wearing public. As opposed to normal vision issues which arise from the light rays being focussed incorrectly by the retina, astigmatism is where the cornea, lens or even eyeball are the wrong shape.
The physical distortion is largely undetectable to others but those who suffer from it suffer blurred vision as a result of the light rays scattering randomly both in front of and behind the retina. It is the random scattering of this light that makes an ordinary contact lens inadequate, and the reason why Toric lenses were created. They solve the problem by combining a series of different shapes to catch the light and enable the wearer to focus properly.
A regular contact lens has the shape of a half sphere, whereas a Toric lens combines a spherical surface with one that is toroidal, or doughnut, shaped. Even though they are a different shape, they are made in all the same materials as regular lenses, hard, soft and RGP, which puts paid to the common misconception that is you suffer astigmatism you cannot get soft lenses.
The big difference to the wearer is that Toric lenses cannot be allowed to rotate round the eye; it has to stay in one place in order to address the problem of the scattered light. To make life easier for the wearer, they are often weighted at the bottom to keep them in place and prevent them from rising upwards. If you have astigmatism combined with another vision problem, the lenses can be created to deal with both problems simultaneously, making Toric lenses one of the biggest breakthroughs in ophthalmology.