Essilor, the world's largest maker of prescription eyewear lenses for improving vision, is offering $12.45 per share in cash for each share of Coastal.
The Canadian company, which has been expanding into sales of prescription eye glasses and sunglasses in addition to contact lenses, said its board is unanimously supporting Essilor's offer.
The deal is expected to close within 90 days after receiving the necessary shareholder and regulatory approvals.
On the Toronto Stock Exchange, Coastal's stock (TSX:COA) was up than 20 per cent from the pre-announcement close, rising by $2.14 to to $12.53 at midmorning.
Essilor's offer was 43 per cent above Coastal.com's three-month, volume-weighted average price of $8.73 prior to Thursday's announcement.
Coastal.com founder and CEO Roger Hardy praised Essilor as a company that shares Coastal.com's "focus on customers, innovation and growth."
"The combination will enhance Coastal.com's ability to achieve its goals while realizing a significant all-cash premium for our shareholders," Hardy said. "I am confident this merger is the right decision for Coastal.com, our employees and our shareholders."
Essilor chairman and CEO Hubert Sagnieres, in explaining the reasons behind the purchase, said "the Internet has an important role to play in helping us to fulfil our corporate mission of enabling people to enjoy a better life through better sight."
"With Coastal.com, Essilor is acquiring a recognized online vision care platform," he said.
Coastal Contacts Inc. is an online direct-to-consumer retailer of contact lenses, eyeglasses, sunglasses and vision care accessories serving more than 10 markets around the world, including Canada, the United States, Sweden, Norway and Japan. It also operates a handful of storefronts in Toronto and Vancouver.
Essilor International SA is a France-based ophthalmic optics company whose brands include Varilux, Crizal, Kodak and Foster Grant among others.
It also develops and sells equipment for prescription laboratories as well as instruments and services designed for optical professionals.