Very Large Pupils and Lasik Surgery

What do most lasik surgeons consider very large pupils? I've read the pupil dilates naturally at night from 5-8 mm. Can it get bigger than that? Just really curious. Cant find a real clear answer about this. Would like some input. Thanks

Doctor Answers 4

LASIK and Pupil Size

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The size of the average pupil is approximately 5mm. In dim or low light the pupil will, typically, enlarge by about 2mm, on average. The use of the femtosecond laser to create the corneal flap, as well as a customized laser to perform the laser correction, has greatly diminished the importance of pupil size. The reason for this is that the modern(2010) laser corrections(LASIK or PRK) have a treatment diameter of approximately 9mm and the surface is so smooth that postoperative glare is greatly reduced, if not eliminated in most patients. Young women have the greatest tendency to have large pupils(> 8mm), but, even then, there is rarely a situation anymore in which pupil size makes a person a noncandidate for laser correction. There is no question that if you search the internet for (LASIK+glare) you will find an endless list of links, however, the vast majority of these links are from cases performed in the 1990's. I had my laser correction performed in 1994 and I have a little bit of glare at night because my treatment diameter was only 6.5mm(that is as much as lasers could do then). My patients today rarely, if ever, complain of glare(also called halos or starbursting) after the swelling goes away(the first week).

Baltimore Ophthalmologist

Pupil Size And LASIK

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most surgeons feel that larger pupils carry the risk of night symptoms after LASIK, but every good study published shows there is no relation

clearly i have many patients who have night symptoms that are eliminated by alphagan, which prevents pupil dilation, so this proves that it is related in these people

the only logical conclusion is that pupil size is not related to night problems in most people, but is in a minority of people, so on a statistical basis there is no relation

modern lasers can go wider, so just make sure your surgeon knows how to go off vanilla and increase the default ablation diameter

i'd really urge you to get LASEK instead of LASIK, because with identical zones, i've found less night glare in LASEK when i switched to that from doing LASIK, simply because you don't have a 2-piece, sandwiched cornea afterwards for the rest of your life, so your night vision is typically a little better after the newer noncutting procedures

Dr Emil Chynn

Park Avenue LASEK

Emil William Chynn, MD, FACS, MBA
New York Ophthalmologist

Pupil size, night vision and LASIK

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Everyone has a different pupil size, and yes of course its larger at night.  Basic physics dictates that larger pupils, with our without LASIK, have worse vision than smaller pupils.  the question is whether LASIK makes this worse.  The short answer is you dont know in advance.  Every eye is different; different prescription, different pupil size, different curvature, etc.  what we do know is that with current technology, there is no direct relationship between pupil size and night glare.  The chances of this issue are sporadic, and fortunately rare.  There may be a relationship with the amount of correction performed and pupil size and glare, ie high corrections and large pupils but again, we are not currently seeing more than the isolated patient with worse glare at night.

All patients immediately after LASIK have night glare and halos.  It improves each week for up to six months after surgery at which point the vast majority of patients do not report a problem.   Hope this helps.

Mark H. Blecher, MD
Philadelphia Ophthalmologist

Pupil dilation varies per person

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Pupil size can range in every person. A few people can have pupils that dilate bigger than 9 mm, but it is rare.

Christopher Coad, MD
New York Ophthalmologist

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.