Cataract side effects

My sister had cataract surgery.

They say it occurs gradually after the age of 40.

I wonder if it's natural..

My sister sometimes has trouble focusing.

But I hear it's better than before.

I was planning to do it after my sister, if it's okay.

The cost is too high because the insurance isn't covering itㅜㅜ

Are there significant side effects from cataract surgery?