Pinguecula, yellowish growths on the surface of the sclera, the white part of the eye, often occur in people who spent a lot of time in the sun. Although most pinguecula occur in middle aged or older people, children can also develop them, All About Vision states.
1 radian = 180 / pi degrees. This cannot be written in the format pi/x. cyberkiwi's answer would be in units of revolution, such that 1 rev is equivalent to a complete circle. Then 1/(2pi) revs would be equivalent to 1 radian.
An alternate definition of radians is sometimes given as a ratio. Instead of taking the unit circle with center at the vertex of the angle Î¸, take any circle with center at the vertex of the angle. Then the radian measure of the angle is the ratio of the length of the subtended arc to the radius r of the circle. For instance, if the length of the arc is 3 and the radius of the circle is 2, then the radian measure is 1.5.