4. Your Eyes Are Dry
By now it should be clear that drinking water affects more than just your mouth and throat. A lack of water intake leads to dry, bloodshot eyes (again, think of that last pounding hangover). Without water in the body, your tear ducts dry up. If you’re thinking “So what if I can’t cry?”, realize that this could cause much more harm to your eyes, especially if you wear contacts on a daily basis.