There are nerve cells which are only used to send visual signs to our brains. These cells can translate messages into vision to our brain However, when our brain is beat badly, these cells will tremble too. In that case, these cells will translate the message in the wrong way, so our brain will see stars. This is normal situation. Because you cough very badly like a thump in your brain, it is easy for that happening. When you see stars in vision after coughing, you can put a pear around you. When you cough badly, you can have the pear and have cough medicine. As cough disappears, seeing starts in vision after coughing disappears as well.