A blind man would be glad to see it.

The remark suggests that the chance to see something can be worth appreciating even when the thing itself seems disappointing or unremarkable.

Its wry force comes from imagining a person without sight welcoming what someone else dismisses. It asks the listener to reconsider a complaint rather than to praise the object.

Use it as a wry response when someone complains that a visible thing is not worth looking at. The emphasis is on valuing the ability to see, not on claiming that the thing is beautiful.