Eye cup and Eyeglass

Eye cup noun - A small vessel with a rim curved to fit the orbit of the eye; use to apply medicated or cleansing solution to the eyeball.

Eyeglass and eye cup are semantically related. In some cases you can use "Eyeglass" instead a noun phrase "Eye cup".

Eyeglass noun - Lens for correcting defective vision in one eye; held in place by facial muscles.

Eye cup and eyeglass are semantically related. Sometimes you can replace phrase "Eye cup" with "Eyeglass", this terms are similar.