I am writing a poem, and need to know the authentic scientific phrase to express the optical effect that makes objects seen up close appear to double, as in the little sausage that appears when you hold your index fingers about an inch apart, an inch or so in front of your eyes. I have been using the term 'binocular parallax' because that is what I thought I remembered from Physics, but can no longer find reference to it, and have no confidence that is right. Upon learning the correct phrase, I'll post the poem (it's not long). Thanks.

davy jones

davy jones