The Color-Sensitive Cones. In 1965 came experimental confirmation of a long expected result - there are three types of color-sensitive cones in the retina of the human eye, corresponding roughly to red, green, and blue sensitive detectors.
Most PGA Tour caddies make between $1000 and $1500 per week, but they also make a percentage of what the player wins in the tournaments. This usually equates to 5 percent of any finish outside the top 10. Players breaking into the top 10, but not winning, will share 7 percent of their prize with their caddies.
Caddies don't have an annual salary like most people do. The President of the Professional Caddies Association (PCA) recently told reporters that high end caddies typically earn a base weekly salary of somewhere between $1,000-$1,500. Again, caddies negotiate this deal with the golfer on a case by case basis.