Dehydration is one of the most worrisome complications of diarrhea in children. Mild diarrhea usually doesn't cause significant fluid loss, but moderate or severe diarrhea can. Severe dehydration is dangerous; it can cause seizures, brain damage, even death. Know the signs of dehydration.
Cough and cold medications and decongestants may cause the eyes to dilate. In general, any medication that is a stimulant may cause the eyes to dilate. While it's not particularly common, this could include ADHD medications such as Adderall or Ritalin. Of course, certain illegal drugs do this as well, such as cocaine.
Long term use of NSAIDS can cause a wide variety of vision related side effects including dry eyes, cataracts and eye hemorrhages. These NSAIDS include Ibuprofen, naproxen sodium, aspirin, ketoprofen, Advil, Motrin, Bayer, Aleve, and flurbiprofen. NSAIDS are also drugs that make your eyes more sensitive to damage from the sun so you should be sure to wear sunglasses to protect your eyes. Not only can NSAIDS make you more at risk for cataracts, but they increase the risk for developing macular degeneration, glaucoma and optic nerve damage.