The reasons are simple and there are several reasons below.
Firstly, you should make sure that the contact lenses whether you wear too much time. In general, contact lenses daily allow 10 hours and then you should take down them to rest the eyes, avoiding eye hypoxia.
Secondly, you should ensure the daily cleaning of contact lenses. Please check the contact lenses clean every day.
Then, you should consider whether you overuse the eyes. Eyes for a long time, it means they do not rest well and you may suffer the dry eyes, which can cause the cloudy vision. As you say, after crying such symptoms become more obvious .Maybe it is a strong reaction comprehensive of all the circumstances.
In addition, it is recommended that you should keep the glasses clean, take down and clean every day. Do not wear contact lenses online for a long time. Note that the period of shelf life and the use of contact lenses do not exceed the period of use. In summary, any kind of bad habits will cause glasses hypoxia, resulting in cloudy vision.