One of the most beautiful words in the Russian language is ненаглядный. If you look it up in the dictionary, you'll probably find something like dear or beloved. That's probably adequate for a fast and dirty written translation, but it entirely misses the image of the word. Let's break it down by first considering how the verb it comes from is made up.

When you add the prefix на- to a verb and also make it reflexive, then it adds the idea of "to do to the point of satiation." Thus начитаться means “to read until you can't read any more,” and наесться means “to eat until you can't eat any more.” Very often these verbs are used in sentences with the negative particle не to catch the idea of “I couldn't get enough of” something. Examples:

The verb глядеть means “to look at,” so наглядеться means “to look at someone to the point of satiation.” It's mostly used with the negative particle не:

Thus the adjective ненаглядный comes from the verb phrase «не наглядеться», i.e. it means “the one you can't stop looking at.” In translation, we have to find some other English phrase that captures the emotion of the comment to really get it right:

Can you picture it? To be so wrapped up in one person, to have that beloved face constantly before you when you wake and sleep... ’tis a madness devoutly to be wished.