What can occur if glasses are not positioned correctly over the optical center of the lenses?

If glasses are not positioned correctly over the optical center of the lenses, a prismatic effect can occur. This happens because the light passing through the lenses is displaced, causing images to appear shifted or distorted. The optical center is specifically designed to minimize distortion and ensure that light is adequately focused on the retina for optimal vision. When the center is misaligned with the line of sight, it can effectively create a prism effect, leading to issues such as double vision or difficulty focusing on objects.

In contrast, other outcomes like increased visual acuity, reduced glare, or better clarity of vision are generally associated with correct positioning of the lenses. These outcomes reflect optimal lens performance rather than the consequences of misalignment, highlighting the importance of proper fitting in eyewear to achieve the best visual experience.