Final answer:
An apical alignment of Rigid Gas Permeable (RGP) lenses helps ensure a comfortable and stable fit, maintains corneal health by facilitating tear flow, and decreases the risk of hypoxia by allowing ample oxygen to the cornea.
Step-by-step explanation:
The advantage of an apical alignment of the Rigid Gas Permeable (RGP) lenses is that it ensures a proper fit on the wearer's eye. In this context, 'apical' refers to the apex or the central part of the cornea. When RGP lenses are apically aligned, they align with the highest point of the cornea, leading to a more comfortable and stable lens fit. Such alignment facilitates the flow of tears underneath the lens, which is important for corneal health and optimal vision. A well-aligned RGP lens can also reduce the risk of corneal hypoxia by allowing ample oxygen to reach the corneal surface, which is crucial since RGPs are less oxygen-permeable than soft lenses. An apical alignment may also minimize lens movement, enhancing the overall visual performance and decreasing the risk of lens displacement or loss.