How does axis rotation affect vision in toric lenses and what stabilization features help?

How does axis rotation affect vision in toric lenses and what stabilization features help?

• A. Rotation misaligns the cyl axis, causing blur; stabilization features like ballast, periballast, or prism help maintain orientation.
• B. Rotation does not affect vision in toric lenses, stabilization isn't needed.
• C. Axis rotation improves vision with toric lenses.
• D. Stabilization features only affect comfort, not vision.

Answer: (B)

In toric lenses, the cylinder axis must line up with the eye’s astigmatic axis. If the lens rotates on the eye, that axis shifts and the corrective orientation is wrong, leading to blurred, fluctuating vision. Stabilization features like ballast (a heavier bottom), periballast (edge-weight distribution), and prism ballast are built into the lens to resist rotation and keep the lens oriented correctly during blinking and eye movements. So rotation does affect vision, and these stabilization methods help maintain sharp, stable vision. Saying rotation doesn’t affect vision or that stabilization isn’t needed isn’t accurate, because the whole point of these features is to preserve the correct orientation of the toric correction.