Pour 1/2 cup white school glue into a bowl
Add 1/2 cup water
Mix well
Add food coloring if desired
Add 1/2 teaspoon baking soda
Mix again
Add 1 to 2 tablespoons contact lens solution slowly
Stir until slime starts to form
Knead with hands until it is no longer sticky
Add a little more contact lens solution if needed
Store in an airtight container