Recently, my dust and morning allergy make my eyes hurt and sore. So, my mom convinced me to go see a doctor. A little transparent spot that floating around in my sight turns out to be "Vitreous degeneration". Most of the floaters are harmless but it can not be treated. However,if I see an increase in floaters or flashing lights that will be more scary.
Therefore, you should check your eyes by look against a white background.
With Love ;)