The two-minute clip shows Corden talking about how to record a charity campaign with The Feel Bad Four method.
Rankin said: "Charity campaigns are saturated with negative images so this film is about making people connect with something, being honest and human."
Susan Adams, director of UK funding and marketing at Sightsavers, said: "Sightsavers wanted to create something that was completely different to anything we've done before.
"But at the same time we wanted to highlight the shocking facts about avoidable blindness and the work that Sightsavers is doing to stop this."
Rankin and Corden worked together with scriptwriter Michael Holden on the campaign.
Sightsavers works to prevent blindness, restore sight and advocate for social inclusion and equal rights for people who are blind and visually impaired.
The charity notes that there are 39 million blind people in the world and that 80% of blindness can be prevented or cured.
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