WASHINGTON -- Between barnstorming the early presidential caucus state of Iowa and a scheduled stop in the key primary state of South Carolina, Sen. Rand Paul (R-Ky.), an ophthalmologist, joined a medical mission this week to perform about 200 sight-restoring cataract surgeries for impoverished communities in Guatemala.

While his aides insist the trip is strictly for charity (Paul raised $20,000 from various donors to help foot the bill), it does gives the possible presidential contender a way to raise his profile, especially at a time when record violence is driving Central American children to the borders of the United States. But the mission also draws attention to policies Paul championed as a newly minted libertarian senator, including proposals to cut funding to the National Institutes of Health and U.S. aid to needy countries like Guatemala.

The Moran Eye Center at the University of Utah, which organized Paul's trip, is the largest eye care facility between California and Michigan. It collaborates with partners around the world on new research advancements designed to cure blinding eye diseases, and its researchers are largely funded by grants from the NIH. In the 2014 fiscal year alone, Moran received 19 awards from the NIH’s National Eye Institute, totaling more than $6.9 million. But in 2012, Paul proposed drastically slashing government spending -- including reducing the NIH budget by 20 percent, or $7 billion, from its 2008 levels.

Paul's senior adviser brushed off any criticism that the trip exposed the pitfalls of his own legislative ambition.

"The Moran Eye Center Outreach Division is a private charity. Senator Paul was thrilled to help both as a surgeon, and to raise funds for their operation," Doug Stafford told HuffPost on Thursday.

Paul also met with Guatemalan President Otto Perez Molina on Thursday. The two discussed promoting investment in the country as well as solutions to alleviate the migration of unaccompanied children to the United States.

The U.S. provides millions of dollars in aid to Guatemala each year -- a funding stream that Paul has criticized in the past. He waged a one-man battle in 2012 against foreign aid spending, which he considers an expensive boondoggle that carries little influence with foreign nations. That position caught up to him earlier this month in Iowa, after he refused to acknowledge that he once supported ending federal aid to Israel.