BALTIMORE � Something remarkable happened in the late innings of an otherwise routine Red Sox-Twins exhibition game at JetBlue Park last Thursday night. Minnesota righty Jared Burton threw Will Middlebrooks a splitter that began in the strike zone an

BALTIMORE � Something remarkable happened in the late innings of an otherwise routine Red Sox-Twins exhibition game at JetBlue Park last Thursday night. Minnesota righty Jared Burton threw Will Middlebrooks a splitter that began in the strike zone and dove out of it. Middlebrooks saw it. He recognized it. He laid off it.

�I just went, �No,�� the young third baseman said. �That�s a pitch that 90 percent of people swing at it. I swing at it. A good split is hard to lay off. When I took that pitch, I was like, �Oh. OK.��

And that�s when Middlebrooks realized that his new contact lenses really were working.

Middlebrooks never had trouble with his vision before. When he was drafted out of high school six years ago, he said, his vision was closer to 20-15 than 20-20. But a test this spring revealed that his vision had deteriorated in the years since � 20-25 in his right eye, 20-30 in his left.

He still doesn�t need corrective lenses away from the ballpark. His vision is more than good enough for everything else he does.

�For everyday life, you�d never correct it,� he said. �But for what I do, you need to be able to see the little things. Once I put them in, I could really see the spin on the ball. I was always just reading trajectory of the ball. I was never seeing the spin.�

Now Middlebrooks can see the spin of a slider. He can recognize the rotation of a changeup. Everything is sharper. A young hitter who knows he needs to recognize pitches than he did last year better now can see pitches than he could last year � giving him a better chance to succeed with the revamped plate approach he�s trying to take into this season.

�I wasn�t consistent with my approach and my way of thinking at the plate,� he said. �That has nothing to do with my vision. That�s just decision-making. But it�s easier when you can see things.�

Two years ago the top prospect in the Red Sox farm system, Middlebrooks hit 15 home runs in fewer than 300 plate appearances as a rookie in 2012 before a pitch broke his wrist in mid-August. He looked poised to assert himself as a middle-of-the-order hitters for a generation.

But he fell flat last season, hitting .227 with a woeful .271 on-base percentage and finding himself shipped back to Triple-A Pawtucket in the middle of the season. He enjoyed a resurgence upon his return to Boston, but he hit just .160 with 10 strikeouts in 28 plate appearances in the playoffs and was benched in favor of Xander Bogaerts midway through the ALCS.

In many ways, Middlebrooks could emerge as the linchpin of the Red Sox lineup. He has enough power to hit 30 homers this year and every year. He can hit the ball to all fields � as evidenced by the triple he launched to the triangle in right-center field on Thursday night.

He just has to have the pitch recognition and plate discipline to force pitchers to challenge him in the strike zone, to throw him pitches he can hammer.

So far, so good. He finished spring training with more home runs (four) than strikeouts (three).

�The thing that stands out to me the most is his willingness to take borderline pitches and not expand as we�ve seen in the past,� Boston manager John Farrell said, and pointed to the decision to wear contact lenses: �Let�s face it, that, to me, has shown a tangible difference, and he�s seeing the ball better.�

With the help of sharper vision, Middlebrooks this spring has tightened up his strike zone so he�s not chasing the pitches off the plate. That has included asking batting-practice pitchers to move the ball around � and out of � the strike zone so he�s working on his recognition even when he�s honing his swing.

�When you go up there with a plan and you have an idea of what you want to do, what you want to swing at, it�s easier to lay off borderline pitches that you may swing at half the time and get called a ball,� he said. �They�re close. They�re right at the knees or just off the plate. Sometimes they�ll get called a strike, but those aren�t pitches you can do anything with.�

Middlebrooks first tried to wear contact lenses in two games about two weeks ago. They didn�t take. He didn�t like the way they felt. He abandoned the experiment.

But after discussion with the Red Sox brass, Middlebrooks gave the contacts a second try this week, starting last Tuesday. He wanted to give himself a week to get used to them so that he could take them into the regular season.

The first time he put the contacts back in, he picked up a Jake Odorizzi changeup on a 3-2 pitch and hit it for a home run.

�That�s more just seeing it out of his hand and reacting � hand-eye coordination,� he said. �I know it�s helping me.�

Adjusting to wearing contacts regularly has not been easy for Middlebrooks. They still make his eyes ache and tear up. They still dry out. He still has to remember to bring sunglasses with him to the plate � something he�d never done before � to prevent the wind from drying out his eyes.

He mistakenly walked out to the on-deck circle without his sunglasses in the fourth inning on Friday. Before he could turn around to retrieve them, Xander Bogaerts had hit a single to left. Middlebrooks had no choice but to step to the plate, squinting his eyes shut as best he could until the last possible minute. He still has no idea how he saw the ball well enough to ground a single to center field � at which point first-base coach Arnie Beyeler summoned the sunglasses from the dugout.

Compared to what he�s trying to do with pitches at the edge of the strike zone, however, remembering his sunglasses seems like a minor adjustment to make.

Twitter: @brianmacp