When my son was little, he used to sit in my lap and I would play his favorite programs on my PC like Ruffs Bone, Hunchback of Notre Dame, The Animals and similar. He would get excited and would want to touch the characters on the screen. I wished he could manage the mouse but he was too young for that and could not even grip a mouse let alone move it. 
I started looking for touch screen monitors but they were expensive. Then I discovered a kit that converts a regular monitor to a touch screen monitor and boy was that money well spent. I mounted the touch screen on top of my regular monitor using velcro strips and connected it’s wire to the USB port on the PC, loaded the drivers and our touch screen monitor was in business.
A child can touch and that’s what makes a touch screen monitor such a useful tool in edutainment – a term used for education and entertainment. The touch screen enabled my son to interact with the software and play and replay his favorite parts. Most of the software titles for toddlers and very young kids are educational and entertaining at the same time. As a result, when my son joined the Montessori, he was way ahead of his age group.
Such touch screen monitor kits are still around. In fact they have them now for laptops as well as desktop LCD monitors. It’s one of the best investment you can make in your toddlers education.
Interloper.com has a choice of touch screen monitor conversion kits. Check with them to see what will fit your monitor.