A FREQUENT CORRESPONDENT by the name of “Martin the Mess” responds to an advertisement for Superior Reading Lamps:

Well, I guess when you’re well into your third century and your eyesight isn’t what it used to be, and you read all those old pre-Victorian public-domain books with their tiny cramped printing and obsolete hard-to-read fonts where the S’s look like F’s and so forth, you need one of those things.

In fact, Dr. Boli, who is indeed well into his third century, has no need of high-powered lamps, making do very well with a pair of quadrifocal corrective lenses of his own design. It is, however, fascinating to consider from a merely scientific point of view the effects of aging on the eyes. It is a curious fact that, in many individuals, the primary effect of aging on the eye is farsightedness, or presbyopia (from Greek terms meaning “priest-eye”). It becomes progressively more difficult to focus the eye on objects nearby, but easier to see things in the distance. The effect becomes more pronounced with advancing age, and, after the first century and a half or so, one begins to notice that it is a temporal as well as a spacial phenomenon. The present is a bit of a blur, but the past appears in sharp focus. Nor is this temporal farsightedness unidirectional: today, at the age of 228, Dr. Boli finds that he can see a century into the future with perfect clarity.