Good vision correction requires proper fitting lenses and Biomedics toric contacts were created with extra attention to achieving a consistently good fit. It doesn't take much of a variation in the eye to cause astigmatism, so it's especially important for toric contact lenses to fit well. And with their unique design, Biomedics toric contacts do just that.

If people who wore contact lenses never blinked or moved their eyes, Biomedics toric contacts would have been easier to make. But every time a person with contact lenses blinks, it tends to shift the lenses slightly. For contacts made to correct nearsightedness or farsightedness, this usually isn't a problem. Most corneas are uniformly spherical and a slight shift of the contact lens doesn't cause a change in its corrective ability.

But a person with astigmatism doesn't have a spherically-shaped cornea. Their cornea or sometimes their lens or even their retina, is shaped more like cylinder instead of a sphere. It's much like taking a balloon and squeezing it. And this uneven curvature is the reason Biomedics toric contacts require such a precise fit and a way to maintain it.

To counteract the effects of blinking or anything which might change the position of the contact lens, Biomedics developed a patented self-positioning lens. The shape of Biomedics toric contacts is such, that the lens is slightly heavier at the bottom than at the top. So if the lens gets rotated one way, its own weight tends to rotate it back into position.