Is there a word or phrase for the feeling you get after looking at a word for too long?

Solution 1:

Eureka! Ok, so it's not a single word, but it's what I was trying to think of:

Semantic Satiation:

Semantic satiation (also semantic saturation) is a psychological phenomenon in which repetition causes a word or phrase to temporarily lose meaning for the listener, who then perceives the speech as repeated meaningless sounds.

I also found a languagehat discussion on this topic.

Solution 2:

Based on this NGram... ...I'm tempted to suggest semantic satiation is a 'failed coinage'.

Personally I think it's misleading to imply the phenomenon is restricted to the issue of semantics in the first place. In my experience it's not so much that the word 'loses its meaning'. It's more a matter of saying that almost any word tends to become 'unusual' if you concentrate on it too long, even while you remain perfectly well aware of what the word actually means.

So given that Leon Jakobovits James's 1962 coinage doesn't exactly seem to have taken off (many of the later usages being simply references to his anyway), I think it would be better to call it

lexical fatigue (or saturation, as used in olfactory/auditory/visual contexts).

This at least has the benefit of making it clear that it's caused by form of the word itself, not the meaning (which may not even be particularly involved).

Solution 3:

The article on semantic satiation led me to the French term jamais vu, which I think I like better for a couple reasons. It seems to apply better to the written form as described in the original question, and also I find it more fun to say.