RNIB launched the #Seedtheneed ad on its YouTube channel on 14 September and subsequently tried to run it on Facebook.
The ad, created by Good Agency, aimed to make people aware about the lack of support for people losing their sight.
The voiceover on the advert sites: "You’ll fear for your job, your home, your life."
Good Agency, which called Facebook "disrespectful" for banning the ad, said: "We wanted to communicate the extraordinary emotions people go through when they are first diagnosed with sight loss in order to emphasise the importance of support at this critical time."
The social media site banned the ad for breaking its guidelines on use of language that is "profane, vulgar, threatening or generates high negative feedback".
Facebook contacted the RNIB today (30 September) and apologised for the error.
A Facebook spokeswoman said: "Facebook is a place for people and organisations to campaign for the things that matter to them, and the Royal National Institute of Blind People’s video ad is a great example of that.
"In this instance we made a mistake, and have contacted the charity to let them know and to apologise for any inconvenience caused".
In a comment on twitter the RNIB said: "We can confirm that Facebook have reversed their decision to ban our ad! Thank you all for your support!"