Age-related macular degeneration (AMD) is one of the most common causes of blindness among adults, particularly in the US where two million people suffer with the condition.
Recent research by the National Eye Institute indicates that the problem may be growing, despite efforts to come up with a cure. The organisation believes as many as three million people in the US alone will suffer from AMD by 2020.
Drug treatments can protect the rods and cones of the eye for a short time, but they are unable to restore the vision that has already been lost, and they often fail in the vast majority of AMD cases.
Some drugs, such as Avastin, were found to increase the likelihood of serious intraocular inflammation - a potentially blinding adverse event - during a study by Dr Sanjay Sharma, a professor of ophthalmology and epidemiology at Queen's University, Canada.
Ingrid Caras, a science officer at the California Institute for Regenerative Medicine, which has invested $50 million (£31.5 million) into funding for stem cell research to treat macular degeneration, said the condition is "high on the priority list of diseases that need attention".
"As our population is aging, the number of people affected is going to grow. And you have people who are otherwise healthy but they can't read, they can't drive - that's a huge burden on society," she explained in the San Francisco Chronicle.
The likelihood of developing AMD in later life is growing as the population is aging, with the risks of blindness a serious consideration for older people.
According to Prevent Blindness America, 1.3 million people over 40 are blind in the US, with the majority, almost 950,000 of them, developing blindness after turning 80.
The issue of AMD in the US has been highlighted by the situation of Virginia Knepper-Doyle, an 80-year-old artist who has had 45 injections in her left eye in the last two years to prevent her from losing her sight.
"The injections had stopped any further deterioration. But suddenly I had no central vision left, and I guess that means the medications don't work anymore," she told the news provider.