Three of their four kids are losing their vision. So, they're going on a year-long world tour to make visual memories, before it's too late

Many parents dream of their children growing up and seeing the world. But Edith Lemay, a mother of four from Canada, worried her children were running out of time to do that.

When her first child, Mia, was little, she noticed she would bump into things. Lemay worried about her daughter's vision and brought her to a doctor. In 2018, Mia was diagnosed with retinitis pigmentosa. 

"What it does is that the cell in the retina dies over time and they lose their field of vision. They're going to lose their vision from the outside to the center and in the end, it's like seeing through straw. And there's a chance they will go completely blind by midlife," Lemay told CBS News.