Loveday Williams has been waiting 11 weeks for treatment but she used to receive her injections at four-week intervals
A "tide of avoidable blindness" could sweep Wales if eye care services are not reformed, a consultant has said.
Gwyn Williams, of the Royal College of Ophthalmologists, said waits for key treatments were "the biggest they've ever been".
Patients told BBC Wales how their sight has worsened while waiting longer than usual for injections.
Health Minister Eluned Morgan said she "puts her head in her hands" every night over the state of the Welsh NHS.
She said she was trying to "get things back on track" and "keep focused".
The Welsh government said access to eye care was being improved with new mobile theatres and community clinics.
Mr Williams told BBC Wales Live the main areas of ophthalmology with "harmful delays" in Wales were macular degeneration, glaucoma and diabetic eye disease.
Latest data shows that more than half of the planned 133,000 appointments for the highest risk eye patients were significantly overdue.
Macular degeneration affects the middle part of people's vision and can get worse if untreated.
"Your eyesight just gets poorer and poorer," said Loveday Williams, 90, from Neyland, Pembrokeshire, who has received regular injections to manage the condition for the last 20 years.
She had previously received them at intervals of four or six weeks but in recent months they have become much longer with the latest, due this week, having taken 11 weeks.
"Looking at things, the TV especially... you notice you have to get closer and closer," she said.
"My knees are nearly touching the table."
She said treatment was the "difference between seeing and not seeing and the thought of not seeing is just terrifying".
"To think of me sitting in the chair not able to see or do anything, it doesn't bear thinking about really," she said.
"I couldn't live on my own if that was the case."