By Sarah Campbell
Reporter, BBC News
Patients making co-payments for some operations on the NHS could be the best way to maintain the service, some doctors argue.
Mr Allen supports co-payments
The scheme would mean patients 'pay the difference' between NHS and private treatments.
Cataracts - clouding of the lens in the eye - affects around 300,000 people every year in the UK.
The corrective surgery involves replacing the defective lens with an artificial one.
The standard lens offered by the NHS corrects distance vision, but most patients will still need to wear glasses for reading and close up work.
When George Coates, 72, visited his eye surgeon two years ago he agreed to have a new type of lens implanted which would correct both distance and close up vision.
In his view the operation has been a total success.
"I had never worn glasses in my life, so to be able to have operation and still continue not wearing glasses to me was a major thing."
Because he was part of a trial scheme George received the new lens free of charge - he was lucky.
As an NHS patient you would be extremely unlikely at the moment to be offered the superior lens, simply because it costs around £500 per eye.
Instead, you would probably have to have it fitted privately at a total cost of around £3,000 per eye.
David Allen, George's eye surgeon, believes there is a cost effective solution.
"My suggestion of co-payment allows those patients for whom not wearing reading glasses is important the option of paying the difference between the standard lens and this new type of lens, instead of having to pay for a completely private operation."
This idea of co-payments is, however, being resisted by politicians and health unions.
George Coates would have paid extra
Mike Jackson, of Unison, said: "Co-payments are about the individual's ability to pay, and so you would have two types of healthcare offered in the NHS.
"One would be the basic service for those that can't afford to pay for the enhanced service - that can't be right."
Former NHS manager Roy Lilley said the scheme might ruffle feathers among those people who were passionately committed to the idea of the NHS providing free healthcare when needed.
He said: "Most people who work in the NHS would be against it because the philosophy is free at the point of use."
However, he said as new and more expensive treatments became available some serious thinking was required about how best to fund them.
Although George is not wealthy, he said he would have been happy to pay an extra £1,000 to have the sight he has now.
"Perfect vision is priceless," he said.