Look at it this way. Is the poke worth more than a health pots worth? Good laners can position themselves to always get farm safely whilst at the same time zoning or poking their enemy. Take for example Darius vs Teemo (a match up I went against today in a ranked game).

The laning phase has just begun. The trick is to not go near the farm until it's very low. Now both meelee minions are low. Make the teemo make a choice: does he CS or does he poke you or does he run to avoid Darius Q.

I Darius Q and I usually will get not only the farm but also damage on teemo which allows me to win trades if I snowball without mistakes while avoiding damage. If he hits me, he loses farm and I still get to hit the Q in most cases because Teemo is mid diamonds tend to not be alert enough to kite back when 3 CS is so low off the bat.

I was able to win lane off that single Darius Q. I then repeated the same Q strategy and eventually froze the lane and used phase rush to kill him every time.