I study Turner's seaport paintings through the cobwebs in my right eye and can't distinguish the blur of his shimmering waterways from my blurred vision. Struggling for clarity, I back away, approach more closely, lift my glasses, settle them on again, move sideways now right now left, Turner insisting I accept his ambiguities, blinding sunlight, dark shadows of hulking ships, reflected moonlight. Worn out, I move to other galleries, to the small orderly Vermeers, light streaming angled through partially open windows, narrow focus on two people, my cobwebs can handle this. In a dim hallway the cobwebs recede and two Holbein portraits are almost too clear, unblemished. Vision only slightly veiled I contemplate Titian's massive wealthy writer, bearded Pietro Aretino, proudly wearing his bulky brown fur trimmed coat, then Rembrandt's smooth cheeked merchant, light enlivening his face, his high white ruffled collar. But now Rembrandt himself, aging, scarred face partially in shadow, eyes in shadow, blurred features, as if his painterís eyesight, too, was fading as I press to meet his gaze.