voltage - Is there a point in adding a 1 Ohm resistor to this LED circuit?

I am trying to figure out an appropriate resistor value for the following circuit.

^{simulate this circuit – Schematic created using CircuitLab}

Input voltage - 3.3v Blue LED, forward voltage 3.3v LED : APT3216VBC My maths tells me that driving that LED at say 12ma, means that the resistor should be:

3.3-3.3/0.012 == 0

Checking with some LED resistor calculators, they suggest a 1 ohm resistor : http://led.linear1.org/1led.wiz

Given my voltage drop, and input voltage, what does the addition of this 1 ohm resistor actually make to the circuit?

Thanks