ANSWER: World Braille Day
                                                                            
Explanation: 
World Braille Day was observed on 4th January 2016 to commemorate the birth anniversary of Louis Braille.  Day also helps people to produce works in Braille language for the visually challenged.  Louis Braille was born in the 1800s and credited with developing the Braille script which helps visually impaired people to read as well as write.