| abstract |
A method and apparatus for making an ophthalmic lens pumps monomer into one end of a gas permeable tube along its interior length while a chamber surrounding the gas permeable tube is maintained at a subatmospheric pressure by means of a vacuum pump. Preferably, the gas permeable tube is made of silicon rubber. Static mixers introduce mixing into the flow of the monomer within the tube in order to expose the bulk of the monomer to the gas permeable walls of the tube. Under such conditions in the gas permeable tube, the majority of the dissolved gasses are removed from the monomer and continue to be drawn out of the chamber by the pump connected to the chamber. The degassed monomer is then transferred into a mold where it is polymerized into an ophthalmic lens. |