A rigid gas-permeable lens, also known as an RGP lens, GP lens, or colloquially, a hard contact lens, is a rigid contact lens made of oxygen-permeable polymers. Initially developed in the late 1970s, and through the 1980s and 1990s, they were an improvement over prior 'hard' lenses that restricted oxygen transmission to the eye.
Rigid lenses are able to replace the natural shape of the cornea with a new refracting surface. This means that a regular (spherical) rigid contact lens can provide good level of vision in people who have astigmatism or distorted corneal shapes as with keratoconus. However, they require a period of adaptation before full comfort is achieved.[1]
RGP lenses have various benefits over soft contact lenses, including better durability, clearer vision, and a lower risk of eye infections, claim Hashemi et al. (2019). However, they demand a lengthier adaption period and more specific fitting.[2]
References
edit- ^ Terry, Robert; Schnider, Cristina; Holden, Brien A. (October–December 1989). "Rigid Gas Permeable Lenses and Patient Management". Eye and Contact Lens Science and Clinical Practice. 15 (4). Contact Lens Association of Ophthalmologists: 305–309. PMID 2680164.
- ^ Hashemi, Sara; Veisi, Hadi; Jafarzadehpur, Ebrahim; Rahmani, Rouhollah; Heshmati, Zeinabolhoda (October 2019). "A CCA Approach for Multiview Analysis to Detect Rigid Gas Permeable Lens Base Curve". 2019 IEEE Western New York Image and Signal Processing Workshop (WNYISPW). pp. 1–5. doi:10.1109/WNYIPW.2019.8923063. ISBN 978-1-7281-4352-1. S2CID 208883581.
External links
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- What Are GP Contact Lenses? by Contact Lens Manufacturers Association (CLMA)