Hand pain can be caused by disease or injury affecting any of the structures in the hand, including the bones, muscles, joints, tendons, blood vessels, or connective tissues. Hand pain is one feature of joint inflammation (arthritis) that may be felt in the hand.
Marijuana and the Eyes. Marijuana has a few key effects on the eyes. One of the most noticeable occurs shortly after smoking the drug: redness of eyes. THC in marijuana lowers blood pressure which dilates the blood vessels and increases blood flow throughout the body.
Marijuana also affects brain development. When marijuana users begin using as teenagers, the drug may reduce thinking, memory, and learning functions and affect how the brain builds connections between the areas necessary for these functions.