Pour 3/4 cup of grape juice into a small bowl and sprinkle the gelatin over the top of it.   Allow the grape juice and gelatin to sit for about 10 minutes just so the gelatin will soften up.  

Once the 10 minutes is done, microwave the mixture for 20 seconds to dissolve the remaining gelatin. 

Pour the remaining grape juice, ginger ale, and gelatin into the bowl, and whisk until all ingredients are fully combined.  If you are making these boozy this is also where you will add the vodka.  

Pour the juice into shot glasses making them about halfway full or at different levels. Place them in the refrigerator and allow them to start setting, this takes about 30-45 minutes. 

Once the shot glasses start to set enough to suspend the eyeballs, put the eyeballs into the glasses, pressing them up against the front of the glass, then slowly fill the remaining glass with the remaining liquid.

Place the glasses back into the fridge and chill for at least 2 hours.  These can be made up to a couple of days in advance.