Second Sight Medical Products Inc. on Wednesday announced it has completed its May 13 rights offering to existing shareholders, which was oversubscribed.

The Sylmar medical device manufacturer will keep $19.8 million of the subscriptions received and return the remainder to investors.

As per the offering, the company that developed the Argus II, a device that restores some vision to those with a certain kind of blindness, will issue about 6 million shares of common stock at a 15 percent discount from the May 31 closing share price or at $3.32 a share.

Second Sight plans to use the money for corporate purposes as well as the continued development of the Argus II and Orion I cortical implant, a visual prosthesis for cortical stimulation the company believes could treat most forms of blindness. Net proceeds from the offering are estimated to be approximately $19.4 million after deducting expenses.

Prior to the closing of the offering, Chief Executive Will McGuire told the Business Journal in an email that the money will continue operations in the short term.

“The $20 million that Second Sight expects to raise in the rights offering allows the company to fund its operations through 2017 and maybe a little beyond,” McGuire wrote. “The rights offering meets the company’s financing needs for the next 12 to 18 months.”

Shares closed down 13 cents, or 3.1 percent, to $4.06 on the Nasdaq.