Big hissy fit from a large section of the fandom. (Not from me; I thought they were great. And come on! It’s more than likely the Monk used sonic shades as well.)
But the behind-the-scenes story as to why they were introduced was sweet, I thought. Moffat believed that the merchandise for the show was getting too expensive for a lot of little kids (and fans of all ages) with limited incomes. So he brought in the sonic sunglasses because most kids probably had access to a cheap pair of sunglasses lying around the house.
I think that was a great idea and I believe there are other ways to avoid buying high-priced toys connected to the show by coming up with your own alternatives.
But they have an incredible look, one that doesn’t need a plastic action figure trapped in a mint-condition box. Your kids could make them at home.
Remember, kids: paint one side first and wait until it’s dry and then paint the other side. Once your aliens are fully dry, expose them to light and you can play with them in darkened settings and have them interact with your Thirteenth Doctor action figure.
For more durability and flexibility, you can cut them out of old flimsy plastic, like discarded shower curtains and even old plastic bags and then paint those up.
They won't be able to stand up on their own, but you could attach them to black construction paper with a base and they'll not only stand up but look brighter against the background.
Just watch out for choking hazards! Ask your parents for supervision to play it safe. There’s nothing wrong in asking for help.
All you’ve shelled out for is the paint really and that’s easy to find at craft shops.