For a festival, I made a couple of these laser eye dolls. It's a fairly quick project to do. In fact, collecting the materials might take most of the time. Let's get creepy!

Supplies

Doll Lasers (2 per doll): simple 3v laser module will do
Battery holder (3v): 2xAA or 2xAAA will do preferably with on/off switch
Toggle switch
Paper
Soldering iron + solder
Drill
Some other stuff: little pieces of wood, tape, iron wire, glue.

Step 1: Picking a Doll

For this project, I bought 3 dolls with a porcelain head. Probably other types of dolls will work too, but make sure that the battery holder fits inside the head and that the electronics are robust against movement of the doll. I choose to use a porcelain head for this reason. Also, make sure that the eyes are separate parts apart from the head since they have to be removed. Of the 3 dolls I bought, I could only make 2 laser eye dolls because for one of the dolls it was impossible to access the inside of the head. So make sure you buy one that has a removable plastic cap on top of the head! (see photos

So, to sum up, the doll must:

- be big enough for the battery holder
- provide some protection for the electronics
- have eyes that can be removed from the head
- have the inside of the head accessible

Step 2: Removing the Eyes

Once you can see the inside of the head, figure out how the eyes are attached to the doll. I only have seen eyes that were glued onto the head, in which case you can probably just press them out (see photo). Note, sometimes it takes quite some force!

Step 3: Intermediate Results: Zombie Eye Doll!

Without the eyes, the doll could already look really cool if you apply some lighting to it (see photo/video)!

Step 4: Making the Laser Eyes: Picking the Laser Modules

Now, we are really getting into it! I bought a bunch of red laser modules (650nm, 3v) from a large electronics component company in the Netherlands, but most likely your own supplier will have them as well. If not, just check Aliexpress. They are really cheap: ~2.00 dollar/ 10 pieces! One thing to keep in mind is that the laser beam should be narrow enough to go through the hole in the doll's eye (see next step).

Step 5: Making the Laser Eyes: Preparing the Laser Modules

Wrap the laser module in a piece of paper and use some tape to finish it. Also, take a piece of iron wire (~40 cm) and bring both ends together. Clamp them by using a vise or some pliers. Use a screwdriver or something similar and twist the iron wire. You should now have a two stranded iron wire with a loop on one side and two open ends on the other side. Place the laser (that was wrapped in paper) in the loop and twist the loop some more to mount the laser to the iron wire (See photo).

Solder the wires of the laser module to the terminals of the battery holder. Make sure that you will connect the correct terminals! The laser module has a diode, so it does matter how you connect the wires. If you don't have a battery holder with a on/off switch, you can easily add a toggle switch to the - or + wire.

Note: The paper has two functions: 1) it provides some compliant material between the metal of the laser module and the iron wire, so that you can clamp the laser module tight by twisting the iron wire. 2) the edge that is created by the paper will keep the laser in place in the next step.

Step 6: Making the Laser Eyes: Preparing the Eyes

If you have access to a column drilling machine, this is the moment to use it. If you are not that lucky to have a fully equipped workshop (that's me), a normal (cordless) drill will do. Get a drill size that is about the same width as the laser's lens, preferably a bit larger. Next, drill the hole as straight and as centered in the eye as possible.

Once you have drilled the holes, shape some pieces of wood so that it will fit on the inside of the doll's head. Drill a hole in the piece of wood that is a bit larger than the laser module's width but smaller than the width of the laser module + the wrapped paper.

Note: Gluing the laser modules onto the eyes is tricky because you won't know if the beams will end up being parallel or not. Instead, to be able to align the laser beams (and also to be able to remove the laser module), I used some wood, iron wire and paper to keep the eyes in place. See the pictures for the idea behind my solution.

Step 7: Finishing Touch

Glue the eyes to the doll again. Hereby, make sure you have attached the wooden pieces! Then, stick the lasers into the holes of the pieces of wood and bend the iron wire such that the lasers stay in place. By moving around the iron wires you can set the target point of the lasers. You can cut the excessive parts of the iron wire. Lastly, place back the plastic cap and the hair of the doll.