Candy that can make you see things?...Sounds crazy and nooo....there are no drugs involved. "Eye Candy" uses the idea of sensory substitution to make you see specific images while eating this candy. Each of our senses sends information to our brain at different frequencies and the brain tells us what to sense by the frequency resonated. Eye Candy has a bunch of resonators on the candy's surface that when placed on the tongue, transmit a frequency that tells the brain and image to see. Currently the candy has 6 flavors or "images" that you can see (ex. a swimming fish, a thumbs up, shooting stars, etc). You can purchase these from Eye Candy's site. (images from Eye Candy)
The idea of sensory substitution is pretty interesting in regards to helping the blind see. In this article on Gizmodo about Eye candy, there was also a video towards the bottom of the post showing a blind man who uses a special camera that makes objects black and white. That image contrast information is then sent to resonators on a device that is put on the tongue. This allows an image to be sent to the brain and the blind man can start to "see" in his brain the images the camera is sending him. I was pretty amazed after I watched the video.