What is the purpose of a prism ballast in contact lenses?

The purpose of a prism ballast in contact lenses primarily focuses on providing stability to the lens on the eye. Specifically, the design of the prism ballast creates a slight weight at the bottom of the lens which helps it settle properly on the eye, thus ensuring that it remains in the correct position during blinking and movement. This stabilizing effect is particularly important in lenses used for specific vision corrections, such as those designed for individuals with certain types of strabismus or for those requiring correction for a high degree of astigmatism.

While enhancing visual acuity, providing comfort and fitting, and increasing light refraction are important features or aspects of contact lenses, they are not the primary function of a prism ballast. The focus of prism ballast on stabilizing the lens distinguishes it from these other characteristics.