Doctors say the government's plan to slash the Medicare rebate for cataract surgery will push thousands of elderly patients onto the public system, putting it under additional strain.
The federal opposition says up to 50,000 extra cataract patients might be forced to seek treatment in public hospitals if the rebate cut goes ahead.
It's vowed to disallow the regulations implementing the change when they're introduced to parliament next month.
The Rudd government announced in the May budget it would halve the rebate for cataract surgery from around $634 to $308.
The changes are due to come into effect from November 1, and eye doctors are ramping up their campaign to block the move.
An Australian Medical Association (AMA) survey of more than 300 eye doctors reveals 81 per cent believe they wouldn't be able to afford to operate on public patients if the Medicare rebate is cut.
AMA president Andrew Pesce says Labor's budget decision is based on poor advice.
"The government believes that most cataract surgery is performed in 15 to 20 minutes - wrong," Dr Pesce said in a statement on Tuesday.
"The government claims that ophthalmologists are overcharging their patients - wrong."
Opposition health spokesman Peter Dutton says the AMA survey is further proof the government should drop its "harsh" proposal to halve the rebate.
"The worrying issue that emerges is that a significant number of ophthalmologists say they will no longer be able to afford to treat public patients," Mr Dutton said.
"That means that more people will have to wait longer or even miss out on treatment that restores their eyesight enabling them to remain independent and enjoy a good quality of life."
Mr Dutton said the opposition would join with independent senator Nick Xenophon and Family First's Steve Fielding to disallow the regulations in the upper house "if the government went ahead".
Health Minister Nicola Roxon insists that's exactly what Labor will be doing.
"The government remains committed to all its budget measures," she said in a statement.
"We will be unable to reform the health system unless we make difficult decisions such as these."
Ms Roxon says the AMA is simply defending its members against a possible salary cut.
On average, ophthalmologists received $585,000 each from taxpayers via Medicare each year, she said.
They earn $154,000 from cataract procedures alone.
"Even after this measure comes into effect they will continue to earn $508,000 from Medicare."
The health minister insisted the rebate was being reduced to better reflect the "real cost" of commonplace cataract procedures.