The number could hit 115M.
Researchers warn that by 2050, the number of cases of blindness worldwide could reach 115 million.
That would represent a threefold increase from the current number of 36 million, the BBC reports.
Growing populations of people who are living longer are the key factor, according to the article, which cites a report published in Lancet Global Health.
BBC notes that sub-Saharan Africa and South Asia are currently among the areas with relatively high rates of vision impairment blindness.
Worldwide, rates of blindness and visual impairment have been declining, "yet the growth and ageing of the world's population is causing a substantial increase in number of people affected," the researchers note.
"These observations, plus a very large contribution from uncorrected presbyopia, highlight the need to scale up vision impairment alleviation efforts at all levels," they conclude.
Read more at the BBC