The number of blind people across the world is set to triple within the next four decades, researchers suggest.
Writing in Lancet Global Health, they predict cases will rise from 36 million to 115 million by 2050, if treatment is not improved by better funding.
A growing ageing population is behind the rising numbers.
Some of the highest rates of blindness and vision impairment are in South Asia and sub-Saharan Africa.
The percentage of the world's population with visual impairments is actually falling, according to the study.
But because the global population is growing and more people are living well into old age, researchers predict the number of people with sight problems will soar in the coming decades.
Analysis of data from 188 countries suggests there are more than 200 million people with moderate to severe vision impairment.
That figure is expected to rise to more than 550 million by 2050.
"Even mild visual impairment can significantly impact a person's life," said lead author Professor Rupert Bourne, from Anglia Ruskin University.
Last year a similar report by the Macular Society ‘Age-related macular degeneration: collaboration to find a cure’, funded by the Clothworkers’ Foundation, predicted that the number of people affected by AMD would rise from 600,000 today to 1.3 million by 2050 – equivalent to 400 new cases every day.
Cathy Yelf chief executive of the Macular Society said: "AMD is the third most common cause of sight loss globally and the most common in the developed world. This is an urgent public health issue.
"The Macular Society is calling for more funding for research into AMD. Macular degeneration represents a huge cost, care and societal burden, yet it does not receive a level of research funding proportionate to its impact.
"Eye disease must be considered a research priority to develop more effective treatments as our population ages and the number of people with sight loss increases to epidemic levels."
- 11.7 million people in South Asia
- 6.2 million people in East Asia
- 3.5 million people in South East Asia
- more than 4% of the population in parts of sub-Saharan Africa
- less than 0.5% of the population of Western Europe