An 88-year-old Devon man is paying up to £10,000 for treatment to save the sight in his right eye because the local NHS has refused to pay.
Jack Tagg suffers from a common cause of blindness in the UK
Jack Tagg said he was told by a consultant that he would not get drug injections unless he had lost vision in his left eye.
Torbay Care Trust rejected the claim and said it operated a "fair" policy.
Mr Tagg suffers from age-related wet macular degeneration (AMD), the most common cause of blindness in the UK.
AMD can lead to blindness in as little as three months, but it can be reversed with prompt treatment.
Mr Tagg is concerned that the AMD if not treated in his right eye could spread to his left eye.
He has now started his first course of private care to save his right eye, which was diagnosed with AMD two weeks ago.
The drug Avastin costs £715 per injection and requires a course of between three and 14 injections over two years.
Mr Tagg said: "I was told that the policy is that when one eye goes, they will fund it.
"It seems to be particularly cruel and callous."
He added: "I think the hospital is magnificent. The fault is with the organisation of the NHS."
Torbay Care Trust said that it was not necessary for patients to be blind in one eye before being treated.
But residual sight had to decline to a limit set by the the National Institute for Clinical Excellence (Nice).
It said that although it could not comment on individual cases, any decision to refuse a patient treatment would only have been reached after "careful examination of the patient's sight and full consideration of the appropriateness of such treatment".
All primary care trusts in Devon had the same policy and the aim was to ensure a "consistent and fair approach".
But Stephen Winyard, of the Royal National Institute of Blind People (RNIB), called on the trust to change its policy.
He said: "The new draft guidance from Nice, issued in December, makes clear that all patients with wet AMD should be treated and they should be treated in the first and second eye.
"Many primary care trusts have changed their policy and are now treating both first and second eyes and that is what we would urge Torbay to do."