Shadow of Heaven by Bob Shaw. Avon S398, 1969. What is the deal with an eyeball in an apple? They liked it so much they used it on the back cover also!
An Ace double-sided book, The Stars are Ours by Andre Norton (a “rip-snorting adventure tale” according to the New York Times!), and 3 Faces of Time by Sam Merwin, Jr. Ace D-121, 1955. Andre Norton is a woman who was the first woman inducted in the Science Fiction and Fantasy Hall of Fame.
The Web of the Chosen by Jack L. Chalker. Ballantine/Del Ray 27376, 1978. This is one freaky cover.
The Voyage of the Space Beagle by A. E. van Vogt. MacFaden Books 60-318, 1963, 1968 printing.
Victory on Janus by Andre Norton. Ace G-703, 1966, 1968 printing.
Beyond the Stars by Ray Cummings. Ace F-248, 1963.
12 Great Classics of Science Fiction, edited by Groff Conklin. Fawcett T-2749, 1963. Another eyeball cover.
I don’t even read science fiction, but I really love the covers.