Your question brings up a lot of interesting topics! Let's clear up some of the important points first.

Light is made up of particles called photons, that travel from a light source to other objects to your eyes. Some examples of light sources are the sun, light bulbs and fire. (But your eyes are not a light source.) Photons are very special particles: we say photons have no rest mass, and you can think of them as energy, not as matter.

Matter (objects, most stuff) is made up of subatomic particles like electrons, neutrons and protons. These particles all have mass--you can weigh them. (Be careful not to confuse protons and photons! Protons have mass, but photons don't have mass.) In most objects, these particles are already combined in a very specific way that we call atoms. All atoms have a core made up of protons and neutrons called the nucleus. Meanwhile, electrons orbit around the nucleus quickly.

Scientists are pretty good at changing the way that atoms are combined with other atoms--this is what chemical reactions do. But it's much harder to change the way that subatomic particles combine together (nuclear reactions). I know a couple examples of places where scientists recombine subatomic particles. In nuclear power plants, we take large atoms like uranium and break them apart to get energy that we can turn into electrical energy. In particle accelerators like the Large Hadron Collider in Europe, physicists put particles inside loops that are longer than 10 miles and race them along the tracks as fast as they can, in opposite directions. Then they smash them together and study the pieces that form or break off.

So here are the challenges that I would face if I wanted to try your request. First, the amount of energy that I would need to start a nuclear reaction is immense. The Large Hadron Collider uses far more energy than any light bulbs in our rooms, so we can't use regular light bulbs as an energy source. Even a really powerful light source like a laser might not be enough to start a nuclear reaction. Plus, it would not be safe to shine that laser into my eyes--the energy would cause enough damage to my eyes to make me go blind.

Next, I would need a way to control exactly which subatomic particles I'm taking and exactly where I'm putting them. A lot of scientists would love to be able to move subatomic particles like Lego blocks, but I don't think we have a way to control them that could affect anything bigger than a few atoms. Even if we solved all of these challenges, you would probably need a strong microscope just to see the wall you made. It turns out that it's much faster and much cheaper to get materials in conventional ways like mining. Even the materials that they used to build the Large Hadron Collider needed to be brought over from various countries.