In sight and Third eye

In sight adjective - At or within a reasonable distance for seeing.

Third eye and in sight are semantically related. in extrasensory perception topic. In some cases you can use "Third eye" instead a noun phrase "In sight".

Third eye noun - A sensory structure capable of light reception located on the dorsal side of the diencephalon in various reptiles.

In sight and third eye are semantically related. You can use "In sight" instead a noun phrase "Third eye".