If you’ve played tennis, or you’ve been watching Wimbledon, or you've ever played fetch with your dog, you know what a tennis ball looks like. You even know what color it is. It’s yellow. Or is it green? First, let’s get the basics out of the way. While tennis balls can be any color, if they’re being used in professional competition, they’re supposed to be yellow. The International Tennis Federation made that rule in 1972, and they’ve stayed that way ever since. So why do people think they’re green? Why do I see different colors? For the sake of this blog, let’s assume we’re only talking about official competition balls. Now, one issue is that yellow is a color that’s best described when contrasted with other colors. For example, a banana in a bowl of fruit or the lines on the street are easy to describe as yellow because they are contrasted with the other hues of surrounding objects of different colors. But standing on its own, without anything to compare it to, a yellow object becomes more difficult to describe. The same occurs with green objects. Also, lighting conditions, and how our brains perceive them and compensate for them, are a factor. Some scientists hypothesize that we make color corrections to see items as stable colors under different lighting. Some people, the theory goes, discount cool colors, therefore seeing tennis balls as yellow. People who discount warm colors, on the other hand, see them as green. And yes, this is the prevailing theory as to why some people saw the infamous Internet dress as white and gold vs. blue and black. We’ll help you see Whatever color you see tennis balls as, we want to make sure you see them as clearly as possible. If you need your eyes examined, don’t hesitate to schedule an appointment with a CEENTA eye doctor today. This blog is for information purposes only. For specific medical questions, please consult your doctor. CEENTA has eye doctors in 12 locations in North Carolina. To schedule an appointment, call 704-295-3000. You can also schedule an appointment online or through myCEENTAchart.