How to See Invisible Ink With Glasses Seeing invisible ink with glasses is one of the coolest things that you can do marked cards glasses. Spies and clandestine lovers have used invisible ink for centuries to convey hidden messages. There are a variety of different invisible inks that can be used invisible ink glasses, and the way in which a message is revealed depends on the kind of ink that is being written. For example, some invisible inks can be revealed with heat (such as putting a paper under an iron or placing it on a radiator), others are revealed when a certain acid is applied to them, and still others are only revealed when they are exposed to UV light.There are a number of common household liquids that can be used as invisible ink. For example, lemon juice is a good invisible ink that can be developed with heat or by using an acid. Other acids such as vinegar, red cabbage solution and even saliva are also useful for this purpose. In addition, any household chemical that can weaken the structure of paper can be used as invisible ink.During World War II, the SOE (Special Operations Executive) secret agents often used invisible ink to pass messages. These agents often worked behind enemy lines, so they had to be able to communicate without being detected. The SOE identified some properties that an ideal invisible ink should have. The invisible ink should be non-volatile, i.e. it should not produce a strong smell. It should be soluble in water and not react with iodine or other common developers.