Bausch and Lomb Soflens 66 Toric contact lenses are designed to treat the most common refractive error of patients requiring correction of their eyesight — astigmatism. Astigmatism is probably one of the least understood refractive errors among the general public. There are two types of astigmatism: regular and irregular.
Irregular astigmatism is generally caused by defects in the crystalline lens or cornea that scatter light. Regular astigmatism occurs as a result of the cornea having a less round, or spherical shape like that of a football. This causes light to focus at two different radii, not allowing a sharp clear ray of light to focus on the retina. This type of astigmatism can be corrected using glasses or contacts.
Toric contacts correct this refractive error by correcting each radii independently allowing light to refocus at one point rather than two. These contacts are weighted, known as prism ballasting, to allow the spherical and cylinder (both radii) prescriptions to be correctly oriented.
Lens rotation is a major factor when fitting toric lenses. Depending on the strength of prescription, lens rotation will blur vision. This often occurs during blinking if a contact is ill-fitting. Soflens 66 Toric contacts are manufactured with a patented design called “Lo-Torque.” “Lo-Torque” allows greater stability during wear resulting in a shorter rotational recovery. Rotational recovery is the amount of time required for a contact to return to its original position after an interruption such as blinking or eye rubbing. This is extremely important for toric lenses since they correct the cornea in two different radii at different orientations to negate the effect of astigmatism.
A survey conducted in 2009 revealed that nearly 80% of contact wearers have suffered from delayed rotational recovery resulting in blurred vision and discomfort. Comparative studies conducted between Soflens 66 Toric and Acuvue Advance for Astigmatism and Acuvue Oasys for Astigmatism demonstrate a quicker average rotational recovery time with less deviation of rotation. On average, Soflens 66 Torics rotated only 4 degrees versus the Acuvue brand products which rotated at between 5 to 11 degrees. This is significant, especially in patients with substantial astigmatic correction, since it may potentially drop the level of acuity several lines on the eyechart. Less rotational deviation and rotational recovery means less time the patient will experience visual disruptions when doing something as simple as rubbing the eye.
Baush and Lomb Soflens 66 Toric contacts are not only designed to address the unique needs of astigmatism patients, but also have a high water content and oxygen transmissibility necessary to maintain good ocular health and comfort. High water content, at 66%, will give the patient a more natural feeling as well as maintaining moisture for corneal health. The oxygen transmissibility, with a Dk value of 32, will also contribute to the overall comfort of lens wear as well as preventing complications which can threaten vision. These benefits afford the patient peace of mind knowing that not only will they see well, but be comfortable doing it.