Most Important 19th Century Invention

I was torn between three very important inventions from the 19th century:

In 1800, Count Alessandro Volta invented the battery. Batteries are used in computers, cars, and many other things. I can't imagine life completely plugged.

Then in 1880 another great invention was created: toilet paper. Without toilet paper we would still be using leaves or be going by the "left hand" rule. Toilet paper makes life sanitary and hygienic.

My last important 19th century invention was created in 1887 by F.E. Muller and Adolph Fick: wearable contact lenses. I wear contact lenses, and they are fantastic compared to glasses. Playing sports with glasses is impossible, not to mention dangerous. Going to amusement parks, swimming pools, and anything that involves sweat or water is so much more enjoyable with the aid of contacts.