Sen. Amy KlobucharAmy Jean KlobucharOvernight Cybersecurity: Bipartisan bill aims to deter election interference | Russian hackers target Senate | House Intel panel subpoenas Bannon | DHS giving 'active defense' cyber tools to private sector Pawlenty opts out of Senate run in Minnesota Nielsen says 'possible' Trump used vulgar language in meeting MORE (D-Minn.) called for more scrutiny over major contact lens makers decision to set price minimums for their products.

“They are an essential part of many people’s daily lives, and these consumers deserve fair prices,” Klobuchar said Monday. “We need to be clear-eyed about how these policies are impacting consumers and competition.”

Klobuchar said the decisions by Alcon, Bausch & Lomb and Johnson & Johnson could limit competition and increase prices for consumers since those two companies control 75 percent of the $4 billion a year U.S. contact lens market.

During the last year, three of the four top U.S. contact lens manufacturers have decided to set minimum sale prices. If retailers try to sell the lenses at a lower price, the manufacturer can stop shipping the product to that store.

Klobuchar said that could be a “major blow” to online and discount retailers.

Before senators left town for a five-week August recess, Klobuchar hosted a Senate Judiciary Committee hearing on the topic.