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