Dawn Thomas, who suffers from a rare degenerative eye condition called PXE, said her family may be forced to sell its home to fund private treatment unless South Staffordshire Primary Care Trust (PCT) pays for care available elsewhere on the NHS.
Steve Winyard, Head of Campaigns and Policy at RNIB, said:
"The refusal of her PCT to fund an effective and proven treatment is a cruel decision that is likely to mean Mrs Thomas has to stop working. There will be a massive impact on her quality of life and a big long term cost to the taxpayer.
"If there's an approved treatment available which will save a person's sight then it should be given to the patient. It's vital that people diagnosed with sight threatening conditions have the opportunity to receive proven and timely treatments."