The vision thing

That's the way I feel about every cool new technology device or application out there, including but not limited to the BlackBerry, the iPhone, texting, Twitter, and so on.

It seems like just yesterday I was explaining to my mother how Internet Explorer allows you to increase the font size: "Um, I think it's over here, on one of these pull-down menus . . ." Then, 10 days ago, I was hunting for that same pull-down menu because I was tired of squinting to read the screen on my brand-new, purse-sized netbook.

Those tiny keys on the BlackBerry? Are you kidding? Heaven knows I'd like to be checking my e-mails during dinner parties or using my cellphone to text friends during school plays. But I'm saving what's left of my vision to read "David Copperfield" in my old age. And not on my Palm Treo!

I know what you are thinking: Here is some blind old gasser complaining that he can't read the 6-point type underneath the 20 icons sitting on the 3.5-inch (diagonal) iPhone screen. I am in fact an old gasser, but I am far from blind. I don't use glasses to read or write. To paraphrase Norma Desmond in "Sunset Boulevard": I'm fine. It's the devices that got small.

"Welcome to the club," says optometrist Dr. Jeffrey Anshel, who consults in the field of visual ergonomics. "I'm surprised you lasted this long." In evolutionary terms, our vision is engineered for about 30 years of use. "Nobody was texting in prehistoric times. We are outliving our focusing ability," says Anshel, who at 59 wears glasses when he uses his cellphone to send text messages.

You are reading this article in text that is 9 points high. That is also the default font size for the BlackBerry. Dr. Jeffrey Weaver, clinical care director for the American Optometric Association, estimates that you can read a newspaper with 20/50 vision. The keys on his Samsun BlackJack digital assistant "are fairly small, but they are within the realm of visual acuity," he says, requiring perhaps 20/30 or 20/40 vision.

"The newspaper is more forgiving in a couple of ways," he says. The print is often larger but is also more readable. "You get much better contrast for the eyes than you do on a digital display."

There is also a huge difference between typing, as I am now, on a regular computer keyboard and thumbing out messages on a PDA. You can type on a computer with crummy vision, as bad as 20/2100, Weaver says. The BlackBerry or cellphone keypad requires greater concentration and much better vision - or glasses.

The dean of American visual researchers is Pacific University's Dr. James Sheedy, who has received numerous research grants from Microsoft. He just completed a study comparing young adults' use of hand-held digital assistants to normal reading. "As you might expect, the smaller the font, the closer the subjects had to hold the devices," Sheedy explains. "They held the digital displays closer than the printed text."

So? "People bring the display closer to make it larger, but you get resistance from the eyes' accommodating and convergence systems. The eyes say, 'You can't bring it that close, it's straining me too much.' "

Sheedy was speaking to me on an Apple iPhone. I asked him to check the font size on the screen. "Yes, it does get down to 6 points," he allowed. So how does the 61-year-old doctor read it? "I need to use my multifocals," he says.

I invited Apple, Motorola, which makes my cellphone, and Barnes & Noble, which owns a company that downloads books onto PDAs, to discuss the "vision thing" with me. All declined. I was especially curious to learn the default type size of the newly announced Kindle book reading application for the iPhone, which is less than half the size of a normal paperback. "That's going to be a damned small image," says optometrist Anshel.

Magnifying glasses not included.

Alex Beam is a Globe columnist. His e-dress isbeam@globe.com.