Glisten: To shine by reflection with a sparkling luster OR be shiny, as if wet.
Gleam: A steady but subdued shining; a glow OR shine brightly, like a star or a light
And just to make it more confusing:
Glisten: To sparkle or shine; especially, to shine with a mild, subdued, and fitful luster; to emit a soft, scintillating light; to gleam;
My own personal take is that glisten means wet. Like Scarlet O'Hara, working an angle with Ashley. Like a mom's eyes at a wedding. Or a 16 year old girl telling her daddy that she got her first ticket. Or my eyes, when I come across a big stack of 30s Vogue magazines. Or my eyes, when I think of how badly I'd like to come across that stack of magazines.........
Gleam, to me, means a wild look in the eyes. Think Jack Nicholson in The Shining. Or a devious, scheming woman. Like Scarlet O'Hara thinking about those drapes. Or carrots.
So let's clarify. I'll show you a couple of pictures, and you tell me if they are glisten or gleam. We'll have a little throw-down right here, and settle it once and for all. Maybe. And if not, at least we can enjoy the pictures.