Silicon Valley venture capitalist Joe Lonsdale has just raised a $640 million fund and plans to spend a good chunk of that in health care.

Lonsdale, who co-founded software company Palantir and backed virtual reality company Oculus, now sees health as the market where start-ups can have the biggest impact addressing some of society's most systemic problems.

In an interview with CNBC, Lonsdale said technology giants like Apple, Google and Amazon have big aspirations in the market, but even bigger hurdles to overcome.

"I'm skeptical of big companies with established cultures coming into health," he said.

Lonsdale has made some early-stage health bets, including biotech start-up Synthego and health insurer Oscar Health. But for his next fund, which he closed in late April, he plans to double down on the space.

One area of emphasis is finding companies that will benefit from the recent shift away from fee-for-service health care, where doctors get paid for tests and procedures, to value-based care, where they get paid for keeping their patients healthy.