India, Oct. 11 -- Optical illusions are one of the biggest trends on Reddit these days. These challenges test one's cognitive skills, eyesight, and intelligence quotient, all at once. The latest optical illusion to leave users stumped asked players to spot a hidden dog in the photo. Though the challenge looks easy, only those with excellent observation skills will be able to find the canine in 10 seconds or less.

The post, shared by user u/two-kidz on the subreddit r/Find the Sniper, shows an image of what looked like a backyard, with a dog standing in the extreme right. The title of the post was 'Dog (s)?', which implied that there might be more than one canine in the photo. The caption of the image was, "First time posting here, wife s...