1. eyeball
それから彼はぐるりと目玉を動かした。Then he rolled his eyeballs around.
2. special feature; centerpiece; showpiece; drawcard
大会の目玉になる事は間違いないだろう。It is undoubtedly going to be the centerpiece of the tournament.
3. special program; loss leader
4. sunny-side up fried egg