Japanese Verb Question?

Question:

In the following sentence why is 見てればいい　used instead of 見ればいい?

悲しみなんて吐きだして 前だけ見てればいいんだっけ。

Is it o.k. to add ーればいい　after the　－て form? Or is there something else going on there that I don't get? Please help; I've been trying to learn Japanese verb conjugations and this is really bugging me.

Answer:

見ている is closer to "(keep) looking/watching" than 見る (look/watch)

見てればいいんだっけ comes from 見ていれば いいの です よね。

..... ば いい is "conditional" form. Check conjugation chart in the following link.
見れ -ばいい and　見ていれ -ばいい are both categorized in Group 2a (上一段 kami ichidan)
http://en.wikipedia.org/wiki/Japanese_gr…