STAAR Surgical plummets after ending planned $1.6 billion merger with Alcon
** Shares of medical device maker STAAR Surgical STAA.O drop 18.9% to $19.41 premarket ** Co says it will terminate $1.6 billion merger deal with Swiss eye-care firm Alcon ALCC.S ** Termination follows failure to secure enough shareholder votes in support of the deal ** CEO Stephen Farrell says co will focus on profitable sales growth ** Up to previous close, STAA stock down 2.4% over the past year (Reporting by Tharuniyaa Lakshmi in Bengaluru) ((tharuniyaa@thomsonreuters.com))