In 2007, researchers at the University of CaliforniaâDavis determined that our Solar System was fully formed at 4.568 billion years ago. They did this by determining the age of stony materials from the asteroid belt.
When to see a doctor. See your doctor immediately if you experience the signs and symptoms of migraine with aura, such as temporary vision loss or floating spots or zigzag lines in your field of vision. Your doctor will need to rule out more-serious conditions, such as a stroke or retinal tear.
Normally, the two eyes point in the same direction. A âsquintâ or âstrabismusâ occurs when the two eyes are misaligned. This can happen in either eye and the misalignment can be in any direction. A squint may occur for a number of reasons. Sometimes, one or more of the muscles that move the eyes is in the wrong place. Sometimes the muscles do not work as they should.