The main symptoms of cataracts include a decline in vision, with both near and far objects appearing unclear, and blurry vision. There is no significant eye pain or headaches, nor does it cause redness in the eyes. If headaches do occur, it is important to investigate the cause, such as checking if there is an increase in eye pressure or if the headache is caused by glaucoma, and to treat according to the specific cause. However, in the later stages or over-mature stage of cataracts, the lens may dissolve, which can potentially lead to phacolytic glaucoma, but this condition is very rare.