The fall in waiting times for cataract surgery has gone too far, with the NHS now spending too much on the operations, eye doctors have claimed.
Resources have been poured into cataract surgery
Huge resources were poured into the area in the 1990s to meet a predicted surge in demand.
Writing in the British Journal of Ophthalmology, the Oxford Eye Hospital team said primary care trusts were now paying for unnecessary operations.
Another expert agreed some operations could wait until symptoms worsen.
Cataracts mainly affect older people, and it had been thought that an ageing population would generate plenty of work for surgeons.
Faced with this prospect, the government signed bulk contracts for thousands of cataract operations with private providers running Independent Sector Treatment Centres.
These proved controversial in some areas, particularly in Oxford, where one local primary care trust at first refused to use the independent centre.
It argued the loss of work from Oxford Eye Hospital could harm their efforts to help more complex cases, and to train the ophthalmologists of the future.
The arrival of a quicker new technique which uses ultrasound to restore eyesight, has helped the rate of cataract surgery increase tenfold over the past decade.
More than 300,000 operations were carried out in the 2003-04 financial year.
The Oxford team say it is now in question whether so many operations are needed, or whether patients are being treated before it is necessary in order to fill up operating theatres.
The researchers wrote: "The fact that cataract surgery has increased so much in recent years raises questions as to whether it is now undertaken too readily."
They suggested that patients should be assessed according to national criteria, and that those whose need for surgery was not as pressing should wait a little longer.
Mike Dixon, from the NHS Alliance, said that the over-supply of cataract operations was the "tip of the iceberg", and that surplus capacity would be a problem in many hospital specialties in the future.
"If you've made a big effort to raise capacity to deal with waiting lists, it is inevitable that that once the waiting lists fall, you won't need as much capacity any more.
"The problem in terms of independent sector treatment centres is that in some cases, they have contracts for a minimum number of cases with primary care trusts running for another couple of years.
"Some PCTs feel a little sore that they are having to spend money that could go elsewhere on something that arguably isn't really needed."
He agreed with the call for GPs to apply a national standard to restrict access to cataract surgery to only those with the greatest need.
A Department of Health spokesman said: "The increase in supply of cataract services has enabled the NHS to massively reduce waits for cataract surgery."