To correct a flat fitting gas permeable lens, which option would be effective?

Increasing the optical zone is an effective method to correct a flat fitting gas permeable lens. When a gas permeable lens fits flat, it does not adequately vault over the cornea, which can lead to issues such as inadequate tear exchange or discomfort. By increasing the optical zone, the lens gains additional central thickness and creates more clearance over the corneal surface. This adjustment can enhance the relationship between the lens and the cornea, thereby improving overall fit and comfort.

In contrast, simply decreasing the lens thickness may not directly address the fitting issues associated with flat fitting; it could even exacerbate the problem by reducing the support needed for proper lens positioning. Flattening the curvature could worsen the fitting as it would make the lens sit even flatter against the cornea. Adjusting the lens color does not have any impact on the fitting characteristics of the lens and is unrelated to the fit itself.