Spaying removes both the uterus and both ovaries and is crucial in the prevention as well as the treatment of mammary cancer. SIMPLE CONVENIENCE. The female dog comes into heat every 8 months or so. There is a bloody vaginal discharge and attraction of local male dogs.
Tired eyes can come from any number of activities. Some of the most common include working on the computer for too long, poor lighting conditions, driving a car for prolonged periods of time, reading for long periods, or any other activity that may require the eyes to maintain intense focus for long periods of time.
Maybe: Our eyes are designed to see things in 3d. When you look at a computer/book etc for a long time (a 2d surface) you can strain your eyes or get dry eyes. Every 20 minutes rest your eyes for 20 seconds by looking at something at least 20 feet away.