Q: My right eye number is -5.5, spherical and 1.0 cylindrical. The axis is -10 and vision is 6/6 and left eye is -5.0, spherical and 1.0 cylindrical. The axis is 170 and vision 6/6. I want to wear contact lenses. My optician told me that if I could not afford toric lenses (which are for about Rs 4000), I could wear normal lenses which cost around Rs 800. Can I go in for ordinary lenses? Will it have an effect on my eyes in the long run? I am planning to wear these lenses for 9-10 months only. What role does cylindrical number has?

A:One can consider conventional (spherical) contact lenses for patients with cylindrical powers of upto 1.0 diopter. However, there may be a slight compromise in visual clarity by this method of correction of the refractive error. There are no long term side effects expected on the eye by using such lenses. Cylindrical powers are generated by the shape of ones cornea (being more elliptical as opposed to being perfectly spherical in shape) and the power difference generated is corrected by the use of cylindrical lenses. Toric Lenses fit better in such eyes, and are therefore the first choice of contact lenses to be used.