ABSTRACT
In the mid-1960s, a Czech polymer chemist changed the industry by making the first “soft” contact lenses from his newly invented HEMA hydrogel material. The dramatically improved comfort over rigid corneal contact lenses changed the contact lens industry in the United States, and ultimately the world, with rigid gas-permeable contact lenses accounting for only about 10% of the lenses that fit worldwide. Many patients had their contact lens wear curtailed due to adverse corneal events precipitated by insufficient oxygen being available to the eyes during their wearing hours. Hyperopic patients may notice the reduction in magnification when moving from a spectacle correction to a contact lens correction but will benefit from the reduced accommodation and convergence demands at near. Contact lenses have highly curved anterior and posterior surfaces to enable them to fit the eye in a stable and comfortable fashion and have a relatively constant alignment with the optical axis of the eye in all positions of gaze.
