I’m using Safari on Mavericks, and have enabled the webgl. On the left I see the cube and the neuron, and I can rotate it and shift up and down through the plane of the cube. But on the right I only see a black and white checkerboard, no outlines to click or color. If I click at random I can maybe hit on a piece of the neuron, but I don’t see the light gray background with black lines. I’ve attached a screen shot.
Welcome to the forum, kentuckienne!
The problem you are experiencing is related to Safari. EyeWire currently only supports Chrome, Firefox and Opera (and on Windows machines even IE11 to some degree).
Is it possible for you to test another browser, maybe? Chrome is the fastest for EyeWire right now, but the other two should work as well.