"〜ができます" and "〜ことができます" convey a similar meaning, but there is a subtle difference in nuance.

〜ができます

This is a straightforward way to express ability or capability.

It directly states that someone or something can do a specific action or task.

スイミングができます

I can swim

〜ことができます

The addition of "こと" (koto) adds a more abstract or general quality to the statement.

It is often used when referring to skills, actions, or activities as concepts rather than specific instances.

絵を描くことができます

I can draw

Both expressions convey the ability to do something, "〜ことができます" may be slightly more abstract or encompassing, emphasizing the capability as a general concept.

見えます　/ 見られます

見えます and 見られます both mean being able to see something. however, 見えます means something naturally comes within your sight without trying, like what you see in front of you right now. 見られます means you have to focus to see it. for example, when you are looking for someone in a crowd and you finally spot them: you can finally see them