Glaucoma is a general term referring to conditions that cause damage to the optic nerve. The most common type of glaucoma is where the intraoccular pressure gets too high and causes optic nerve damage. There are genetic factors as well as blockages preventing from release of pressure within the eye. Glaucoma tends to be a chronic condition that slowly degrades eyesight into tunnel vision.
Catarcts are the clouding of the eye lens (supposed to be transparent), which causes blurred vision. Possible causes are age and excessive UV exposure.