(RTÉ) – Hundreds of landmarks around the world have been illuminated with blue lights tonight to mark World Autism Awareness Day.

In Ireland, the National Concert Hall, Kilkenny Castle and the Department of Education turned blue.

The ‘blue’ day is part of a United Nations initiative to heighten awareness of autism and promote a global conversation on the topic.

It is thought one in 100 people in Ireland are on the autism spectrum, a neuro-development disability that affects the development of the brain in areas of social interaction and communication.

Last year over 18,600 buildings lit-up blue to shine a light on autism including the Sydney Opera House, the Empire State Building and the Great Pyramids in Egypt.

Minister of State at the Department of Health Kathleen Lynch said that she hoped tonight’s events would help to raise awareness of autism among the general public.

She called on local authorities to also participate in awareness-raising by lighting up civic buildings.

See the article and additional photos HERE at RTÉ News