As the years begin to add up, many photographers notice some less-than-happy changes.

The image in the viewfinder is not as sharp and clear as it once was. Focusing, whether by range finder or the ground glass in a single lens reflex, is more difficult and less precise.Numbers for shutter speeds and lens stops become hard to handle, and even the exposure counter becomes a fuzzy guessing game.

Often, it's just the wear and tear of all the years; but sometimes, the problem is more serious, such as cataracts or glaucoma.

With few exceptions, though, none of these problems need mean the end of a photo career or hobby. Medical science and camera technology can provide surprisingly effective solutions.

If problems begin to surface, as they did to me, the first step is a visit to a good ophthalmologist, a medical doctor who specializes in problems of the eye.

The doctor may find that your eyes are healthy and that you need only a change in your lens prescription. Or, he may discover a cataract clouding the eye's lens or glaucoma developing from an increase in the fluid pressure in your eyes.

Cataracts are easily dealt with thanks to various surgical techniques. The problem of glaucoma is not as easy. Glaucoma cannot be cured, but medication and, in some cases, surgery can stop the deterioration and preserve sight.

Sadly, there is one eye problem that can bring the end of a photo career - age-related macular degeneration.

That disease, most of whose victims are over 50, causes atrophy of a small area of the eye called the macula, which is responsible for the sight in the center of the eye - in other words, right in the viewfinder. Although complete blindness does not result, picture-taking days are over.

It seems unnecessary to mention it to a photographer, but regular examination and necessary treatment are essential to keep a camera career going.

And, let's not forget that modern camera technology has done wonders for eyesight that limps a little. Autofocus cameras and brighter viewfinders have been of great help, even in cases where medical science cannot restore perfect vision.

I switched to autofocus before my cataract surgery, and found that my Nikon N8008 could deliver a sharp image faster and better than I could, even in my best days.

The computer-fed LED panel on top of this camera, like that of many others, displays speed and lens settings and other data in large, easy-to-read form.

It all boils down to this: When your eyesight begins to dim, there is usually no need to abandon photography as a career or a pleasure.