It's always difficult to produce hard and fast rules with English. But there are often two words (or stems) for things, one from the Germanic roots and one from Latin (either via Norman French, or from later scientific etc. addition) which leads us to see with our visual system. The older Germanic words tend to be for more commonplace vocabulary, whereas the Latin tends to be for more formal or technical usage (YMMV). But because the inputs to English are mostly indo-European these two roots are sometimes similar anyway.