California brothers Jimmy and Jace Papenhausen have been colour blind all their lives, unable to distinguish shades of red, green and orange, which all look about the same to them.
But that all changed recently when their parents bought them a pair of sunglasses called EnChroma glasses, which can make colours appear more vibrant.
As soon as the first brother, Jimmy, tries the glasses on and looks at the multicoloured balloons and towel his dad and brother are holding, he dissolves into tears.
After hugging his brother, Jace tries them out too and his reaction is much the same.
“It’s so bright… it’s so different,” Jace says between tears, as he and his brother hug again and sob.
The tear-jerking video has been viewed more than 196,000 times since it was uploaded by the brothers’ dad a few weeks ago.
About 10 per cent of the population is colour blind – or colour-vision deficient, as doctors call it -- and can't perceive as many colours as those with normal vision.
The condition mostly affects men and is due to a missing or mutated gene on the X-chromosome.
There are different forms of the condition, but most who have the most common form of red/green colour blindness can correctly identify just five crayons from a standard box of 24.
The makers of the EnChroma glasses say their glasses can help because they have specialized lenses that filter out specific light to make colours appear brighter and more saturated.
The glasses don't work for every form of colour blindness but for about 80 per cent of people with the condition, the glasses help them distinguish certain colours more accurately.
