Rigid gas-permeable (RGP) lenses are contact lenses that are made of a rigid, oxygen permeable material. Unlike soft contact lenses, RGP lenses do not conform to the shape of the eye, but instead maintain their shape and provide a clear, stable vision.

Rigid gas-permeable (RGP) lenses are typically used by individuals who have certain types of vision impairments that cannot be effectively treated with soft lenses, such as:

• Keratoconus: a condition where the cornea becomes thin and bulges into a cone shape, causing distorted vision
• Astigmatism: a condition in which the cornea is irregularly shaped, causing vision to be blurry or distorted
• Presbyopia: a condition where the natural lens of the eye becomes less flexible, making it difficult to focus on objects up close

Additionally, RGP lenses can be used as an alternative to soft contact lenses for individuals who are allergic to the materials used in soft lenses or who have trouble keeping them moist.

However, RGP lenses are not for everyone. It's recommended to consult an eye care professional to determine if it's a good option for you.