Spin casting tends to decenter in which direction?

Spin casting tends to decenter in which direction?

• A. Temporally (toward the temple)
• B. Nasally (toward the nose)
• C. Inferiorly (downward)
• D. Superiorly (upward)

Answer: (A)

In spin casting, the lens material is flung outward by centrifugal force as the mold spins. This flow causes more material to accumulate toward the outer edge on the temporal side, while the optical zone can shift in that direction. The result is a tendency for the lens to decenter toward the temple. The other directions would require different flow biases or orientations that aren’t typical of standard spin casting, so temporally decentered is the most common outcome.

In spin casting, the lens material is flung outward by centrifugal force as the mold spins. This flow causes more material to accumulate toward the outer edge on the temporal side, while the optical zone can shift in that direction. The result is a tendency for the lens to decenter toward the temple. The other directions would require different flow biases or orientations that aren’t typical of standard spin casting, so temporally decentered is the most common outcome.