It happens to quite a few people that their eye colors get lighter when they cry. There are two main explanations for this kind of phemonenon. First of all, the eyes may get red after crying, and the redness may neutralize the original color of your eyes. For example, the brown and red are a pair of complementary colors in proximity which can makes the brown eyes appear lighter. The other explination is that the pupillas of human eyes will get larger when they are crying, thus making the iris of the eyes which determines the eye colors becomes larger. But the amount of the pigments that the iris contains are limited. Therefore, the pigments have to be distributed much thinner and wider, thus making the color look lighter. It is quite normal, do not have to worry about it.