The questions regarding David Ortiz' eyes came fast and furious, with many of the answers emerging as Friday progressed.

Ortiz' problem, which he first referred to Thursday in Detroit, stemmed from dry eyes experienced during certain at-bats. While waiting for pitchers to begin their delivery, the Red Sox' DH would often find himself blinking more than usual, throwing off his focus.

Ortiz doesn't wear contacts, the glasses he dons don't carry prescription lenses, and as Red Sox GM Theo Epstein pointed out, there is no history of poor eye-sight for the slugger. Simply put, Ortiz doesn't know how this problem came about, what kind of affect it has had on his hitting, and what he can do to solve it.

That's where Dr. David Kirschen and Dr. Daniel Laby come in.

The two opthomologists have been under the employment of the Red Sox since before the 2004 season and are the ones who have determined the good and bad of each player's eyesight.

"Everybody is different," Laby said. "Everybody has a different issue and a different problem."

Monday, it was determined by the doctors that Ortiz' eyes were in good condition, needing just eye drops to correct his recent conundrum. It was good news, but not all-together surprising. Just a few months before most fears had already been put to rest thanks to some of the most all-encompassing visual testing in the baseball business.

While Laby wouldn't speak in specifics when it came to individual players, the doctor offered insight as to exactly how he and his partner make determinations regarding potential vision problems.

One thing is clear: The doctors' determination back in February that Ortiz' eyesight wasn't an issue didn't come haphazardly. It is a process that takes each player approximately 20 minutes to complete, and is perhaps the most thorough in the majors.

"The first thing is we go through the regular medical issues -- contacts, having trouble seeing the ball -- then we sit down and we have a system that kind of runs by itself," said Laby, who also tests the Sox' minor leaguers, as well as some of their draft prospects. "We don't have an operator that prompts them, but they have to answer on their own."

"We put up these circles on a computer screen that have a piece missing and the missing piece is left, right, up or down. Then there is a little box where they look at the circles, and as the circles get smaller it's hard to tell where the opening is. The better they do, the smaller the ring gets, and it gets smaller, and smaller, and smaller, and it gets so small they can't get it correct. By the size of the ring we can tell if someone has 20-20, 20-15, 20-12, 20-8, or even 20-40. We do it with the left eye and then the right eye."

But what perhaps separates the work of Kirschen and Laby is what follows. There are a litany of tests that are more baseball-specific than what had been implemented previously. As Laby explained, "You couldn't test as good as you needed to test for baseball because the tests just didn't exist. They only went to 20-15 and these guys are all 20-12 or better."

"We do something called 'depth perception stereovision,' which is two different tests. Then we go on to test eye-preference, if they're favoring one eye over another eye. Then it goes on to test contrast sensitivity, the ability to detect something in a background, such as the seams of the ball or a pitcher's fingers on a ball. We probably have six different tests of contrast ability, which is a little more important than sharpness of vision in order to pick up spin, finger position, and to identify what the pitch is."

One example of a program used by Kirschen and Laby is something that flashes the image of a hand holding a ball with a certain grip (with an unnamed Dodgers pitcher serving as the model), forcing the participant to identify the pitch being implemented. Then there is something that forces the player to keep a small ball inside a rapidly moving circle.

The procedures have not only proven effective in the baseball world, but the doctors also have been contracted by the United States Olympic Committee to apply their craft with those athletes.

Recently, Olympic softball player Tairia Flowers credited the doctors' program with helping decipher that her right eye was a bit weaker than her left, which was hurting her depth perception. And five years ago, it was former Red Sox outfielder Manny Ramirez who saw the payoff from the procedures.

Ramirez asked for a meeting with the doctors in June of the 2004 season, complaining that his vision seemed just a bit off. After some consultation, Kirschen and Laby came up with an exercise that included four Wiffleballs on a hoop that would be thrown at Ramirez, who would have to show enough hand-eye coordination to catch whichever colored ball was called.

It is an exercise that Ramirez uses to this day.

"It wasn't as though his vision was bad, he was seeing the pitches like he always was," Laby said. "But come June of '04 he was not feeling like he was seeing and approaching the ball as well as he had been. That's when we came up with the rings, and that worked for him."

Now Ortiz is hoping the doctors' latest solution can work just as well.