Bobby Lashley can't grow hair in any part of his body due to a medical condition called Alopecia, if you look closely, you'll notice that Lashley doesn't have eyelashes or any visible hair on his body.

Franklin Roberto "Bobby" Lashley (born July 16, 1976) is an American professional wrestler and mixed martial artist. He is currently signed to WWE, where he performs on the SmackDown brand. He is an eight-time world champion, having been a two-time WWE Champion, two-time ECW World Champion, and four-time TNA World Heavyweight Champion. Lashley is also known for his mixed martial arts (MMA) career in Bellator MMA and Strikeforce.

During Lashley's previous WWE run, he had real eyebrows and for a brief time, he even sported a beard during his MMA days

For those who're wondering, the eyebrows we see on Lashley today are tattooed. Some fans thought they were drawn on, but that's not the case.

Lashley is one of those guys who sweat a lot even before the in-ring action begins. This causes issues for Lashley and makes it harder for him to wrestle in the ring as all that drips into his eyes resulting in blurred vision. It's the eyebrows' job to protect us from sweat, and since Lashley doesn't have those, he constantly has to wipe them off from his eyes. 

Being bald doesn't help him either since the lack of hair makes it easier for sweat to get into his eyes. It's the main reason why he wore a sweatband during his TNA run and early days of his 2nd run with the WWE.