possible to change size of text cursor?

Hello. I am wondering whether it's possible to change the size of the text cursor? It looks fine for default-sized text, but when you use the cursor with a small font in a large edit box, they no longer seem to match up.

Does the height of the text box set the cursor's height, or is it related to the font height, or is it universal? Is it possible to adjust the height manually?

Thanks very much