This means, their lost vision could have been avoided.
This is according to the Rapid Assessment of Avoidable Blindness (RAAB) report in PNG.
The report also highlighted that from this 40, 000 blind, twice as many are women. And the higher prevalence of blindness is in the Highlands region, due to inaccessibility to proper health services.
Dr Amyna Sultan from the National Prevention of Blindness committee revealed these results yesterday.
She said the leading cause of blindness in PNG is cataract - a simple operable condition.