Staar Surgical rises after Stifel upgrades to 'buy'

** Shares of lensmaker Staar Surgical STAA.O rise 5.1% to $21.9 premarket

** Brokerage Stifel sees sales growth upside from adoption of company's EVO+ lens in China and recovering international demand; upgrades stock to "buy" from "hold"

** Raises PT to $31 from $28, a premium of 49% from its last close

** Says expectations for future sales are too low as growth in China remains strong and improved overseas demand

** Cites co's overlooked growth potential from its ICL technology portfolio, including opportunities in the large age related vision condition (presbyiopia) market - Stifel

** Four of 12 brokerages rate the stock "buy" or higher, seven "hold" and one "sell"; median PT is $27

** As of last close, stock down 9.6% YTD