Crystalens HD - Stereopsis Problems

[vmfy101]

I recently had Crystalens HD implanted (March 2009) on my right eye. The resulting distant vision was very good (20/20 vision) but my near and intermediate distance vision are so-so. But that is not what I am concerned about. My problem is that since the Crystalens implant on my right eye, I am having difficulty with Depth Perception (Stereopsis).  I have difficulties perceiving distance between objects like going down stair steps,  and I can no longer play volleyball or play tennis since my depth perception is so screwed up.  I feel like I am cross-eyed.

I have complained about this to my doctor one since day but he thinks that it is because the other eye needs to be implanted too. Currently, my left eye has Accuvue Bifocal Contact lens (-9.0  +2.5).  In order to match the left and the right eye,  my left eye actually needed a -9.5 for 20/25 distance  but since Accuvue only makes -9.0 for bifocals, I had to use a straight contact of -9.5 without bi-focals.  Both of my eyes feels they are closely match and can see very well on distant objects but it feels weird because my right eye's horizontal axis feels like it want to go to the left more while my left eye sees straight.

It doesnt appear that both eyes are parallel when i look to far distant objects. Then when i switch to see near objects like in arms lenght, it takes a second or two before both of my eyes converge and when I start to look back to a far distant object, then it once again takes time for my brain to process the difference hence my depth perception is all screwed up.  My doctor says its because of the difference in image size that both of my eyes sees since one uses an IOL and the other uses a contact lens. I question the validity of that because if I pull my right eye away to the right with my hands, it feels better.  I think that the Crystalens HD was put too far in to the left on my right eye (Horizontal-axis). I am afraid that even if the left eye gets a new IOL, that it will still have the same problem.  I'd like to hear your opinion.

As far as the Crystalens HD is concerned, I am disappointed with the near vision  response considering that its supposed to improved the near vision. My doctor have given me some workbook to exercise my eyes  hoping to train them to see near better.  Its been 9 - weeks since surgery but the cross-eyed feeling has not changed since day one.

Any advice?  

Thanks in advance.


This discussion is related to Crystalens problem seeingnafter "tweaking" by DR  .

[John C Hagan III, MD, FACS, FAAO]

Depth perception (stereopsis) is a function of TWO eyes each receiving an image of similiar size and clarity that a normal visual cortex can fuse them and create a 3D world. Again assuming a person has normal stereopsis anything that messes up size or clarity inone eye will mess up true 3D vision.

JCH MD

[JodieJ]

I can only offer some non-professional input.  I've read that the combination of an IOL and a contact lens does produce impaired depth perception (even when both eyes are set for the same target).  I've also read that having two different types of IOLs can impair depth perception.  I suspect that there's a wide range of sensitivities to impairments in depth perception, and you're obviously very sensitive.  I think your best bet is to follow Dr. Hagan's advice (above).

[vmfy101]

Dr, Hagam,

In your honest opinion, do you think what my doctor is saying makes sense? If so, why is it that I never had any issues while wearing contacts on both eyes with my left eye slightly out of focus for distance to compensate for better reading? If one is out of focus while the lother is in-focus, then their image sizes would also be slightly different, but I never felt cross-eyed then. I think this is standard practice so we can see far and near.

I dont know the technicality and parameters used to prescribe these IOL's but what I really think is happening is that if the Crystalens was inserted but not properly centered (Horizontal axis) or the prescription is slightly off axis just like a prescription eyeglass not properly grinded to match the axis of your eyes, then it makes sense that will cause this kind of visual problem.

Do you see what i am saying?  If you dont, please help my doctor explain to me why I am seeing this way?  Even though my vision are good on each eye, I really cant see very well. If I pull the sides of my eye apart, it somehow it feels a little better. Its really weird. I'm surprised that not too many in this forum are experiencing what I am experiencing.

Thus, another question come to mind - what happens if I use a different type of IOL on the left eye - such as Rezoom, Restor, or Tecnis?  Will that also cause this problem? It is necessary then for me to use another Crystalens HD on the left eye? BTW, I see a lot of glare and flairs at night when the light source is at 10 and 2 oclock positions such as street lights or overhead lights at the gym or football fields.

Thanks for any opinion you can share with me.

[John C Hagan III, MD, FACS, FAAO]

In this case your problem will likely persist until the other eye is done. The choice of IOLs is up to you and your MD

JCH MD