When I get comment reply notifications, I normally prefer to read them in context of my own reply, and potentially other replies. However when I do this, the notification doesn't go away on its own, so I have to return to the page to click "mark as read".
I know I can also mark the notification as read by voting on or replying to the reply, but I often don't do that. Yet I always seem to want to view the comment in its context, which requires me to leave the notifications page. In this specific use case there is no convenient way to mark the notification as read without going back.
To avoid the extra page load, I would like the notification being marked as read when the link to it is opened, to be an option. (Actually, I'd like it to be the default behaviour, but since the current default behaviour is to not mark comments as read until an explicit action is taken on them, I suppose I'm in the minority. An option is just fine.)