ᐅ Closing open basement windows

Hello,

I have the following problem:

I have a more or less open basement that I now want to close off. There are large basement windows, but they are only covered with bars, so there is no actual window! This means that dust, rain, animals, etc. all get into the basement.

Until now, I had large plexiglass sheets in front of the basement, but where I live there is always a lot of wind and sun, and the plexiglass eventually got damaged over time.

WHAT options do I have to "close" these basement windows? It obviously needs to be bright enough, so light should still come in.

Also: as cheap as possible, because it’s a rental property! So nothing expensive or permanent.

Thanks. max

I am a tenant, but I am in Italy, where things are somewhat different. I didn't actually rent the basement, so I can't expect the landlord to waterproof it.

Attached are two pictures of the basement windows.

Hi,
I had a similar problem with my house and ended up using louvered grilles as a solution. They block dust and prevent animals from getting in, but it doesn’t feel damp or musty because air can still circulate. The slats also allow enough light to come through.