The conflict shows up in draft meeting minutes included in a document packet prepared for the upcoming spring meeting of the National Council of Insurance Legislators.

NCOIL's Health Insurance and Long-Term Care Issues Committee held a session on vision care benefits during an earlier meeting.

Dr. Jon Pedersen, a representative from the American Optometric Association, told state lawmakers at the meeting that two big VBMs now control about 70% of the vision care market.

"When the VBMs have this market share, it does dictate and limit choices for patients and providers, and it interferes with the patient-doctor relationship," Pedersen said.

Dr. Tommy Lucas, a representative from the Texas Optometric Association, said the big VBMs may force optometrists to use VBM-owned labs.

Lisa Anne Hurt-Forsythe, a vice president at the National Association of Vision Care Plans, questioned whether any "VBM" exists.

"That is not a thing," Hurt-Forsythe said. "That is a manufactured acronym that is designed to create an analogy between vision care plans and pharmacy benefit managers, but there really is nothing similar about the two. PBMs operate largely in a black box. People don't know what's going on. They don't save money for folks; they're a cost driver."

Vision plans, in contrast, operate in a world where prices for vision care products and services are falling, and optometrist practice competition is increasing, Hurt-Forsythe said.

"We're sort of one of the few bright spots in healthcare from a price and a consumer perspective," she said.

Oklahoma, Texas and at least 25 other states have adopted VBM legislation backed by optometrist groups, and members of Congress recently introduced a bill that could set similar rules at the federal level.

The laws would keep a VBM from requiring an optometrist to use specific vision care product and service vendors.

Related: Bipartisan dental and vision plan network bill returns in House

Pedersen and Lucas told state legislators they would like to see more states adopt laws similar to the Texas VBM law.

Hurt-Forsythe pointed out that vision plans are challenging the constitutionality of the Texas VBM law in the federal courts.

What it means: For employers and their benefits advisors, the takeaway is that many different types of care providers are watching pharmacies' conflict with the pharmacy benefit managers closely and trying to borrow policy-shaping ideas.

Employers have concerns about the impact of overly aggressive care management strategies on provider supply in some markets while still wanting to protect care managers' ability to be tough negotiators.