Don't worry. It is usually smog in cities and frost or water vapour in the country side. Or, it can just be a natural occurrance in the eyes when you look at bright objects. A third possibility is that you are just tired. If you are still unsure, go see a doctor.
Actually it is circular but usually the sun needs to be quite low in the sky for the angle of the sunbeams hitting the raindrops to be suitable to create a rainbow visible from the ground. But, when that happens, a part of the rainbow is cut-off by the horizon and so it appears semicircular. Full circles are rare but have been seen/photographed.
The rainbows usually appear after a rainstorm because when you are at a certain angle with relation with the sun and water droplets it creates a rainbow.
RAINBOW usually occurs because of the refletion of the light of the sun.
Usually people think that there is gold at the end of the rainbow. (It's a myth.)
Usually circular.
Usually people think that there is gold at the end of the rainbow. (It's a myth.)
Unicorns may live at the end of a rainbow if they choose but that's usually leprechauns.
A gasket may or may not be circular, and it is usually flat on both sides. An O ring is always circular, and circular in girth as well.
They are usually called the bases.
around the eyes and lips
A butterfly generally represents someone who is transgendered or transexual. A rainbow usually stands for gay pride.
Usually not. A part of a circular shape will not.