Source Site (EDGAR) 424B1

Excerpt From
KERAVISION INC /CA/
Form: 424B1   Filing Date: 8/13/99

<DOCUMENT> <TYPE>424B1 <SEQUENCE>1 <DESCRIPTION>FINAL PROSPECTUS DATED 08/12/1999 <TEXT> <PAGE> Patents and Proprietary Rights One of KeraVision's primary strategies has been to develop a strong proprietary patent position with respect to Intacs technology. As of June 30, 1999, KeraVision had 141 pending patent applications worldwide and had been awarded 25 United States patents and 51 foreign patents. These issued patents and pending patent applications cover various aspects of Intacs technology, including Intacs corneal ring segments, methods of use, instruments and related materials, as well as other vision correction technologies. The expiration dates of the United States issued patents range from 2002 to 2016. KeraVision's policy is to protect its technology by, among other things, filing patent applications relating to important aspects of its Intacs technology and other vision correction technology. KeraVision has entered into confidentiality agreements with its contract manufacturers to protect the proprietary nature of its technology. </text></plaintext></document> </body> </html>