For an MRI of the head, you lie with your head inside a special machine (scanner) that has a strong magnet. The MRI can show tissue damage or disease, such as infection or inflammation, or a tumor, stroke, or seizure. Information from an MRI can be saved and stored on a computer for more study.
what has been seen cannot be unseen. The act of witnessing something so traumatic or disturbing that it is futilely wished to be unseen. Most commonly experienced on 4chan's /b/ or senior citizen dating websites. Me: Oh hey, look, some Nigerian dude emailed me a file called BlueGoatseWaffles! Maybe its a picture of blue goats doing people stuff...like cooking waffles! Me: What has been seen cannot be unseen.
When light from the laser (a luminous object) strikes the suspended water droplets (the illuminated object), the light is reflected to students' eyes. The path of the light beam can now be seen. With light, there can be sight. But without light, there would be no sight. None of us generate light in the visible region of the electromagnetic spectrum. We are not brilliant objects (please take no offense) like the sun; rather, we are illuminated objects like the moon.