PORTLAND, Ore.—Startup firm Sightbox, which offers an annual membership-linked supply service for contact lens wearers, recently raised $2.4 million in new funding to support its growth, a spokesman confirmed.

The new funding round – which included investments from Rogue Venture Partners, Portland Seed Fund, Jumpstart Foundry, Vista River Healthcare, G Ventures and Irish Angels – brings the company’s total funding to $4.2 million. In addition, individual angel investors from the United States participated in the new round of funding, the spokesman confirmed.

Under the parameters of the Sightbox membership model, members pay a monthly fee of $39, which covers an annual eye exam and contact lens fitting, as well as a 12-month supply of contact lenses of their choice. The company coordinates exam appointments and filling prescriptions for members, also.

As VMail reported, Sightbox raised $1.8 million in a seed-round of funding late last year. A portion of the new investment is earmarked for customer acquisition and additional staff across finance and operations, the spokesman confirmed. Sightbox currently has about 20 employees.