Ista Pharmaceuticals Inc., the maker of eye medications, rose 7.9 percent after agreeing to be bought by Bausch & Lomb Inc. for $500 million. Ista climbed to $9.04 at the close of trading in New York. Bausch will pay $9.10 a share in cash for the Irvine, California-based company, 8.6 percent more than the closing price yesterday. Ista, which sells Istalol for intraocular pressure and Bromday for issues associated with cataract extraction, earlier this year rebuffed a $327 million hostile bid by Valeant Pharmaceuticals International Inc. Bausch’s offer is 134 percent more than Ista’s share price on Dec. 15, the day before Valeant’s bid became public.