Halloween LED eyes

[sirmako72]

I'm extremely new to trying things with LEDs...read, never done it.  I picked up a couple of pairs of blinking eyes for Halloween that run off of two AA batteries.  The Christmas tree light bulbs inside them killed my batteries in one evening and I would like to swap them out for a pair of LED lights (if possible).  The circuit has the two lights in series with an on/off switch coming from the two 1.5v battries.  My questions would be 1. is it possible?  2. is it as simple as getting the right LED to go into the curcuit?  3. how would I do this?  The current set up has the eyes blinking but if needed I could go with something that is constantly on and it would look fine.  I was hoping to have this done by Halloween so I can use these this year, but overall it's a learning experience so any help would be greatly appreciated.

Thanks.
Nick

[cadstarsucks]

2 in parallel...  constant on is certainly easier as all you need it 2 resisters, but a simple schmidt oscillator will work fine for you... I do not remember if the 555s most hobbyists like will run at 2-3V from the 2AAs

[sirmako72]

Thanks for the help.   I ended up switching to a 9v supply instead as it just made it easier to fit what I wanted with the brightness I wanted for the eyes.  I also kept to a constant on LED (will look for blinkers for the other pair of eyes, but the ones I found weren't bright enough).  I used the LED calculator for the set up and it suggested in series with a 100ohm resistor and so far it looks pretty good.  It probably would have been easier if I had a clue how to solder