Which is an advantage of rigid gas perm lenses over soft lenses?

Rigid gas permeable (RGP) lenses provide superior optical quality compared to soft lenses due to their ability to maintain a consistent shape on the eye. This rigidity allows RGP lenses to provide sharper vision by minimizing distortions that can occur with softer materials. The precise curvature of RGP lenses helps to maintain a stable tear film beneath the lens, which enhances visual acuity.

Additionally, RGP lenses allow for better management of certain refractive errors, such as astigmatism, because the lens can be specifically designed to correct for these conditions. The material itself is also less prone to warping over time, which helps maintain the accuracy of the optical correction provided.

In contrast, while soft lenses offer advantages in initial comfort and ease of adaptation, they tend to follow the shape of the eye more closely, which can lead to variability in optical performance. Thus, while they may be comfortable for many users, they may not provide the same level of optical clarity and stability as RGP lenses.