Some clinics did not address the problem of dry eyes, Which? reports
People may not be properly advised on the risks of laser eye surgery and might pay more than the advertised price, a Which? study suggests.
The magazine sent researchers into 18 clinics, including several branches of three high street chains.
As well as discrepancies on price, they reported staff at clinics played down possible risks and complications.
Optical Express, one of the companies visited, said the report was "misleading and unfair".
More than half of the 18 consultations were rated unsatisfactory by the consumer group's panel, who included a laser eye surgeon and two clinical researchers.
Issues included staff not addressing the problem of "dry eyes", and failing to mention the risk of longer-term damage dry eye surgery might cause - although there were branches of Optimax, Optical Express and Ultralase where this was raised.
Staff making remarks such as "things cannot go wrong" and apparently dismissing the risk of infection of inflammation were also highlighted as unprofessional by the panel.
Clinics were also criticised for failing to tell researchers that as they reached middle-age they were likely to need reading glasses despite having had surgery.
Which? claims almost half of their researchers were not told about this, despite asking whether they might need glasses after surgery.
The report also pointed to discrepancies between advertised prices and actual cost.
Optimax and Optical Express advertise prices from around £395 per eye - £790 for both - but the lowest price offered was £1,090 at one branch of Optical Express.
Discounts of up to £200 for immediate bookings were questioned by the panel, as was an anecdote about one 19-year-old researcher being "pressured" into contacting her parents to obtain a deposit.
Optical Express noted that the £395 per eye offer had already been investigated by the Broadcast Advertising Clearance Centre and not found to be misleading, as the price was applicable to a significant number with mild visual problems.
It also defended its policy for pre-surgery consultations as "robust" and said quotes from conversations may have been taken "completely out of context".
"Some of these remarks may simply have been benign reassurance - we don't know the full discussion," said Dr Steve Schallhorn, the company's chief medical director. "Basing the report on a sample size of only four visits is not good science."
"We make sure patients fully understand the procedure and that they go into surgery with their eyes open. As well as a face-to-face consultation they also receive a lot of information in the post. It's simply not a fair depiction at all."