Could Lasik Help Dan Uggla?

I have a share in Dan Uggla – one I acquired earlier this year in an attempt to boost my power numbers in the ottoneu FanGraphs Experts League. The results have been mixed, and missing Uggla for at least a couple weeks now won’t help. But Uggla is not overly expensive in that league ($14) and a boost from Lasik could make him a keeper in the off-season.

Yesterday, Eno Sarris made me very sad when he tweeted out some bad news. A study from 2005 with evidence that Lasik was not helping MLB players. But I had some questions upon reading the study.

Before getting too far into this, I should note that I am by no means and medical (or statistical) researcher, and that my writing today is more meant to raise questions than to claim that the study in question is flawed. But I saw three potential issues in what I read, and what I found subsequently gave me some hope that Uggla could come back better than he was before.* Sample size is clearly an issue here, but since the study mentioned that directly and since there isn’t much we can do to solve this, we’ll focus on the others.

Issue 1: Age
The study does not directly consider the impact of age on the players in question. The 12 players whose stats are outlined in the study had an average age of 30.1 at the time of the surgery, but the range is from 24 to 38. The fact that Larry Walker saw a decrease in production from his age 37 to age 38 season may not be all that surprising. Same for Wally Joyner in his after 35 and 36 seasons.

Issue 2: League Context
This study looks at raw hitting data, rather than adjusting for league context. A number of these surgeries happened 1999 and 2000, and looking at 1-2 years before that vs. 1-2 years after may not be the best sample if you are not going to adjust for context.

Issue 3:Two Year Periods
While I understand the sample size issue with only taking one year before and one year after, anyone who wears glasses knows that a year can make a big difference in your vision. A player who was an all-star in Year 1 with great vision, could have vision issues in Year 2, be back to himself thanks to surgery in Year 3, and then fall off in Year 4 simply due to the passage of time. We don’t know enough about these players to say that this is the case, but I am not sure that it is all that meaningful to say that a 33 year old Bernie Williams, two years post-surgery, was worse than a 29 year old Bernie Williams who may have had great vision.

For my own mini-study, I a) added players ages to my table, b) removed Todd Dunwoody, whose career seemed to not justify being in this group, and c) used wRC+ to adjust for league context. The table is below:

Player Age at Surgery 2 Yrs Prior Yr Prior Yr After 2 Yrs After
Larry Walker 38 121 156 135  
Wally Joyner 36 134 121 92 96
Greg Vaughn 32 124 95 151 116
Bernard Gilkey 32 102 74 117  
Al Martin 31 112 71 107 102
Jeff Bagwell 31 162 166 153 143
Bernie Williams 31 158 149 138 141
Mike Lansing 30 110 69   47
Frank Catalanotto 26 95 109 129 111
Jose Cruz 25 98 100 94 118
Trot Nixon 25   109 109 131
Avg 30.6 121.6 110.8 122.5 111.7

The blank spots are years in which guys did not play or did not accrue more than 200 PA.

The first thing that jumps out is that league context offensive contribution went up by a wRC+ of 11.7 in the year after the player had the surgery. That’s no joke. In 2013 terms, this is taking Nate McLouth, Albert Pujols, Mike Napoli or Eric Hosmer (interesting group with wRC+ of 111) and turning them into Nelson Cruz, Billy Butler or Jean Segura (wRC+ of 123). It is a sizable change. They were, on average, still better in year four than in year two.

We can also break this down further. There are three players 25 or 26 years old, six who are 30-32 (Uggla, by the way, is 33), and two who are 36+. The two senior-most gentlemen went from a 138.5 average wRC+ in Year Two to 113.5 in Year Three, which is no surprise given their age. Everyone else went from 104.7 to 124.8 and stayed at 113.6 in year four.

But maybe counting three mid-twenties guys isn’t fair either. Only focusing on the players roughly in Uggla’s age range (30-32), the six players presented went from a 104 wRC+ the year before surgery to 133.2 the year after. Greg Vaughn drove much of this himself, but Bernard Gilkey saw a big jump, too.

All in all, the sample size is still small and the data is still rough, but when we account for age and league context, the picture gets quite a bit rosier. Maybe the way I am looking at the data suggests I need the surgery more than Uggla does, but I am not ruling out the possibility that we will see noticeable gains once Uggla can see. I’ll be watching him closely down the stretch and if he seems to have a better eye at the plate, seems to be making more contact, and sees an uptick in his production, I’ll be accounting for that in my valuation of him for 2014.

*Note that I mean before the surgery, not before the Marlins traded him and he went from star to just really good hitter.




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11 Responses to “Could Lasik Help Dan Uggla?”

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  1. that says:

    Can Lasik actually hurt Dan Uggla?

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  2. harpago17 says:

    I’m not sure if the other cases really apply to Uggla’s situation. While the other guys presumably wore contacts prior to their surgery and had the surgery as a elective procedure, Uggla never wore contacts prior to the 2013 season. He started wearing them this season specifically because of vision problems, and is now opting for the surgery because even with contacts he was experiencing blurry vision. The lack of comparable situations leads me to believe that we don’t know WHAT to expect when Uggla returns, because it’s possible that his problems aren’t even correctable via surgery. One of those things that we simply have to wait and see on.

    On a side note, has any team had more vision problems in recent years than the Braves? Brian McCann struggled for a few years with a bad Lasik surgery, and Freddie Freeman struggled a portion of last year with cornea scratches as a result of dry eyes (he now wears glasses on the field to help prevent anything getting in his eyes).

    Braves might want to look into finding a new optometrist.

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    • Underwood4000 says:

      Re the side note: That could also be a function of the Braves’ medical squad paying more attention to that kind of thing than other teams. It’s possible that other teams simply aren’t catching vision problems when players struggle. (It’s also possible the Braves are overprescribing vision-based treatments; it definitely seems like an opportunity for further research.)

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      • harpago17 says:

        That’s certainly possible, but in McCann and Freeman’s cases in particular they were forced to miss games the problems got so bad, so I’m not sure either of those were overprescribing. Both were a result of dry eyes, although McCann’s was due to LASIK while Freeman’s was due to dust getting into his eyes while in the dry air in Colorado.

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  3. Kyle S says:

    I think one question here is whether eyesight is the problem with Dan Uggla. Looking at his player page, his o-swing % and z-swing% are similar to his normal level, as are his walk rate. Presumably if he were having eyesight problems these might be down, although that is an assumption. His BABIP is down to about .220, so it seems like some of his struggles are just bad luck.
    His LD% is down and his K% are up, which may be the evidence that he’s not seeing the ball well and squaring up as well as in the past, but can one differentiate that from other potential causes such as general aging and slower reflexes?
    Still, if this provides a psychological boost, maybe that will help…

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    • Ruki Motomiya says:

      Vision problems could mean that he is having trouble actually trying to hit the ball, even if he sees it coming (Since it is blurry and makes it hard to see the exact location), so he is making very bad contact or missing the ball (Striking out).

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  4. Fastpiece says:

    Maybe Uggla sucks this year and he’s buying time. MY EYES MY EYES

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    • Keep Brian McCann and dump Struggla (Uggla). Who is having an absolutely horrible year, maybe he is using his vision as an excuse even so a 180-195 batting average for the whole season I mean let’s be real.

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  5. Chris says:

    Due to his age and the fact he has never worn vision correction before this year, he is likely hyperopic. Hyperopia is much more difficult to fix with refractive surgery than myopia.

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  6. SD LASIK says:

    I know a bunch of athletes that come in and get their LASIK done here at the San Diego LASIK Center® and none of them have ever complained of having problems with their vision.

    The only thing that athletes have to keep on top of is that the LASIK could come undone if you play a very physical sport where your eye could get brushed. The “flap” could come undone and you would have to come in and get it fixed, not fun, so for boxers it’s not good, but for basketball, football, baseball players that can wear protective eye wear it’s fine.

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  7. Eye clinic says:

    I support what SD LASIK said.. LASIK is just making a flap on the lens via Excimer Laser method which is the more safe and precise approach.

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