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Dr. Rick
Dr. Rick, Board Certified MD
Category: Eye
Satisfied Customers: 10553
Experience:  Ophthalmology since 1994 with Retina sub-specialty interest
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my 2 and a half month old has partial bioinidase deficiency

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my 2 and a half month old has partial bioinidase deficiency ( which may have nothing to do with my eye question but maybe worth noting). my friend recently pointed out that in the dim lights she has 1 pupil that dilates larger than the other. I have since been paying close attention and noted that dim light her her left eye dilates larger than her right, and in bright lights her left eye constricts smaller than her right. in moderate lights they seem to be the same size in general. her vision seems normal and she can focus on objects and follow them in unison. they each respond and react to light. she had a check up with her pediatrician yesterday who didn't see any major difference as it is subtle but is present in dim and bright lights. can this just be genetic and be normal or could it be a sign of some serious problem? please help so I can start to relax.

Dr. Rick :

Hi. I'm online and happy to answer your question today.

Dr. Rick :

are you available to chat?

JACUSTOMER-hcliq6j5- : Yes
Dr. Rick :

She is most likely suffering from physiologic anisocoria.

Dr. Rick :

Does the difference seem to be very small, on the order of a millimeter or so?

JACUSTOMER-hcliq6j5- : what does that mean is it serious?
JACUSTOMER-hcliq6j5- : yes the difference is small and pretty subtle. in general you don't see a difference at all except for when it is extremely dilated are extremely constricted
Dr. Rick : much difference in pupil size would you say you are noticing?

JACUSTOMER-hcliq6j5- : I would say about a millimeter
Dr. Rick :

Ok. Nothing to worry about. This is just a normal variation in pupil size.

JACUSTOMER-hcliq6j5- : Really? Is there anything I should watch out 4? is it normal that they are not always different sizes all the time and only in extreme dilation or construction?
JACUSTOMER-hcliq6j5- : that is constriction
Dr. Rick :

There is a 99.7% chance that what you are seeing is a normal variation. Of course, I can't see your child but from what you are saying that is the most likely thing you are seeing. Of course, the way to be 110% sure is to have your child evaluated by a pediatric ophthalmologist......

Dr. Rick :

I do not believe that, in an otherwise healthy child, that this is sign of any serious underlying pathology.

JACUSTOMER-hcliq6j5- : okay. is that is what it is is it genetic? I will probably take her to a specialist just to be sure but in the meantime are there any sickness fine I can watch for, like if her vision seems to be a challenge or her eyes are not moving in unison cetera?
JACUSTOMER-hcliq6j5- : ...any symptoms...not sickness fine...
Dr. Rick :

There is no underlying sickness that would cause this minute difference in pupil size where your child would be otherwise normal, especially since your child was just evaluated by a pediatrician yesterday. I think the best thing you can do right now is stop worrying. If I thought you needed to worry, I would tell you to, ok?

Dr. Rick :


JACUSTOMER-hcliq6j5- : Ok. This is my second child. You would seancody more relaxed. I guess ignorance really can be bliss. I will take her to specialist just to be sure but in the meantime I'll try to relax. are there any eye exercises I should be doing with her just to help develop her sight?
Dr. Rick :

I really don't mind scaring young mothers if I have to, 'ya know ;o), so since I'm not trying to scar you, you are ok....

JACUSTOMER-hcliq6j5- : Ha. Yes, I understand. last 2 questions then. in your opinion will this variation be present in her for her entire life? and is there anything I can be doing to help developer vision?
Dr. Rick :

Nope. Just get her into the habit of reading....too few kids do that now a days. My wife and I raised 5 kids, so I know what you are going through. I dragged my first son to a pediatric ophthalmologist because I saw a white flash in his eye during a family picture -- I was convinced he had retinoblastma and was afraid to examine him myself. Well, of course he was ok

Dr. Rick :

Yes, she will most likely have it forever. And, no, there is nothing that has to be done as it will not affect her in the least.

JACUSTOMER-hcliq6j5- : ha that does make me feel better. I guess too much knowledge really isn't power sometimes. :-)
Dr. Rick :


Dr. Rick :

Have a great day and congrats on #2.

Dr. Rick :

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JACUSTOMER-hcliq6j5- : thank you
Dr. Rick :

My pleasure

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Customer: replied 5 years ago.
Hi Dr. Rick,

Thank you for your chat regarding my question on this last week. I have made an appointment with a pediatric ophthalmologist but she won't be seen until February 18. In the meantime I have a few pictures of my baby's eyes (since you were working blind (no pun intended) with my original question. As you will notice, her left eye's pupil is a bit larger than her right. It is more apparent in dim light (and in brighter light the same eye actually constricts smaller than the right as well) but in moderate light the difference appears nominal. I have attached a pic that was taken with a flash so that you can actually see the retinas to make out the size difference better (but with the flash, the difference is much smaller since they are both a bit more constricted) but with the dimmer light picture (even though it is more difficult to see the detail without the flash) you can still tell that there is a much more pronounced size difference (I outlined the 2 pupils to the best of my ability in photoshop in one image...the original of that same image I attached as well just for your review). You may also note that she does not have any apparent ptosis (although at times her right eye does seem to open wider than her left and her left can seem a bit "squint-ier" than the right).

I know you gave me some feedback already but I would love to get your professional opinion with actual images of her eyes since it will be so long before I can get her in to be examined.

Thank you in advance for your assistance.
KelleyKasha pupils regularkasha pupils with color circleskasha pupils flash

Hi. Only the last picture came through.....maybe only only one picture at a time? In the last picture, however, I can see that the left pupil is larger then the right one. It is, however, not such a great difference -- at least in this one picture -- that I am concerned. The difference in pupil size is consistent with physiologic anisocoria.


Can you send me the other pictures again? If they won't load here try using this web site:



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Upload your picture to the site by browsing for it as directed.

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Copy the link inside this box and then paste it into your justanswer dialog box and send it to your expert.

Customer: replied 5 years ago.
Thank you Dr. Rick,

Below are the links of those previous photos from my photobucket. As I said it is much more difficult to discern in the dim light (by the simple virtue that the light is dimmer and much harder to get a clear picture without the flash) but that is when the difference is most obvious. Also, it is still anisocorsia when the same eye (that is usually bigger in dim light) can also be smaller in very bright light? I am not sure if my eyes are just playing tricks on me, but sometimes it seems like the size difference in dim light can vary between the 2 eyes...should the difference always be consistent?

Also, I just attached an additional pic that demonstrates the left eye a bit squintier than the right...I don't think it is ptosis as neither eye ever really covers more of the iris (or any of the pupil) than the other...but I just wanted to include it to be thorough for your review.

I really appreciate you taking the time to review these pics to give me a fuller professional assessment.

Thank you.


Thanks for those pictures. I was able to see them all.


I agree, in all the pictures your daughters left pupil is slightly larger then the right. In reviewing all of them I do not think you have anything to worry about.....It still looks like physiologic anisocoria (which is normal) to me. Of course, when you take her to the pediatric ophthalmologist he will be able to dynamically evaluate her pupil function in controlled lighting condition and know for sure. I would suggest you bring pictures, like the ones you've showed me, to the appointment with you.


As to the squinting, that does not look pathological to me -- just looks like the way she smiles :o)


To answer your question it is normal for the difference between the size of the pupils to vary.....nothing to worry about. Remember. If you need to worry, I promised to tell you, right? ;o)


Take care and drop me a note and let me know how Kasha's eye appointment goes.


Have a great day.

Customer: replied 5 years ago.
Thank you very much. I will keep you posted. You have been helpful!! :-)

My pleasure.


Cute kid, by the way ;o)

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