The Eye: what was it?

[Mnemosyne]

Hmm...

I know that in this chapter especially Sam's point of view dominates, but Frodo was still the character who supposedly recorded all of this. Might his perception of the Eye be some side effect of his Ring-enhanced perception, much like the wheel of fire which apparently manifested itself on a physical level to him?

At any rate this eye-like imagery still comes from a window in the top of the tower and is very faint, not this dumb lighthouse-style searchlight thing that looks like nothing so much as a mussel prized from its shell and stuck between the outer tines of a fork...

What does weird me out with all the canon descriptions of the Eye is how very catlike it is, when the last time Sauron was described in catlike terms he was Tevildo!