So here’s my beef on scissors. Being a left handed person I always wondered why I couldn’t use most pairs of scissors as effectively as some of my other friends…who all happened to be right handed. Apparently it’s all in the fingers. As seen above, the yellow pair of scissors is a right handed pair. When used in the right hand the scissors function correctly as the fingers push the blades together in a vertical fashion. When used in the left hand the blades actually get pulled sideways and cannot function that way. This is why left handed scissors (The red ones in the photo above) must have the blades reversed in order to be used properly by a left handed person.
Source: http://en.wikipedia.org/wiki/Scissors#.27Handed.27_scissors