Japan Atomic Energy Research Institute

Yasuji Sejima

Isao Kaetsu

Minoru Kumakura

Yoshihide Komaki

Ryuji Arai

Tsutomu Sakurai

Takashi Ohno

Toshiyuki Itoh

Hideo Kohyama

In order to make hard and soft contact lenses having a pore diameter and a pore density optimum for use as oxygen permeable contact lenses, the contact lens after molding is subjected to irradiation of a polyvalent heavy ion beam having a mass number of 2 to 100 (preferably 10 to 80) and an ion energy of 10M eV (preferably 50M eV) or higher, at an ion radiation density of 10 to 10.sup.9 ions/cm.sup.2 (preferably 10.sub.2 to 10.sub.5 ions/cm.sup.2) and thereafter ultrasonically etched (preferably at 10 to 50 MHz) at a temperature of 4 to 50.degree. C. (preferably 10.degree. to 30.degree. C.) in the presence of chloroacetic acid (preferably tricholoracetic acid).

Porous contact lens and method for making it

Growing community of inventors

Chofu, Japan

Yasuji Sejima