Are Dilating Drops Always Necessary?

Are Dilating Drops Always Necessary?

Well, yes.  It is always necessary to dilate the pupil for a thorough exam of the retina.  A dilated pupillary exam is part of a thorough examination of the eye.  Without dilation, it is near impossible to see any structures of the retina through the tiny, 2-3 mm, undilated pupil.

All my patients need to be dilated because I am a retinal specialist.  Most of my patients have macular degeneration or diabetic retinopathy.  Without dilation I could not examine the retina properly.

As part of the initial screening when a patient arrives at the office, dilating drops are instilled into one or both eyes.  The patients are then escorted to a separate “dilating” room.  Patients may read, watch TV or talk until dilation occurs.  Usually this takes about 15-20 minutes, bur variations do occur.  Once the pupils are dilated, patients are then moved to an examination room and we complete the office visit by examination with me, the doctor.

Why do the drops take so long to work? There are a few reasons for the varying times a patient may wait before complete dilation.  There are both physiologic reasons and practical reasons.

Physiologic reasons include the patient’s age and the color of their eyes (color of the iris).  Young patients with darkly pigmented (e.g. brown eyes) eyes take the longest to dilate. They are slow dilators.  Why?  The muscles that need to be relaxed by the dilating drops are the strongest at younger ages.  Also, the pigment in darkly colored eyes absorbs the dilating medicine and, thus, it takes longer for the medicine to exert its effect.

I don’t discriminate, but the dilating drops do. The corollary to the slow dilator is that blue eyed, older patients do not take much time to dilate at all.  Sometimes this may be as fast as 5-10 minutes.  You can imagine the nasty looks I sometimes get as I am seeing patients out of turn, simply because some patients dilate faster than others.

There are some diseases or situations where dilation also takes a lot longer than normal.  Some patients simply don’t respond well to the drops.  Patients with uveitis (inflammation inside the eye) also take a long time to dilate.

Sometimes I cheat by having some of my patients arrive dilated.  I don’t suggest this for a routine exam because it is often very difficult to accurately assess vision.  After I operate, I usually instill dilating drops in the operating room.  Patients arrive to the office, the next day, already dilated.  The exam is usually very brief.

There are practical reasons for longer dilating times. Occasionally, doctor’s offices run behind.  I try to run my schedule as fast and efficiently as possible, but sometimes we can’t do it.  On occasion, we might blame slow dilating for the reason for a longer waiting time.  (Ok, don’t quote me on this one or I’ll deny it.)

Others ways to examine the retina are available, but none as good as a dilated exam allowing direct visualization of the retina.   Ultrasound may be used to determine if the internal structures are in the right position.  A retinal detachment, for example,  may be diagnosed by ultrasound.

Non-dilating (so called non-mydriatic) cameras are available.  These devices are able to take pretty good pictures of the retina through an undilated pupil. They are quick and used for screening purposes.  If an abnormality is seen, then a complete dilated exam is warranted.  It is not good enough for the detailed examination required for patients with diabetic retinopathy or macular degeneration.

In conclusion, fully dilated examination is essential to a proper exam of the retina.  Other techniques just don’t provide the information we get by directly viewing the retina.  It does take a longer time, and at our office we warn each patient about the necessity of dilation.

Thanks for your patience.


Randall V. Wong, M.D.
Ophthalmologist, Retina Specialist

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  • J P Hickey
    Posted at 11:50h, 16 October Reply

    Very interesting information on the variance in dilation times.

  • gale long
    Posted at 08:41h, 05 November Reply

    What do you think about drops that reverse the dialation— given after the exam- make it easier for patients to resume activities sooner? Are they safe or an added expense?

    • Randall V. Wong, M.D.
      Posted at 09:36h, 05 November Reply

      There are drops that reverse dilation, but most practices have given up using them. They are expensive, patients complain of burning and don’t remain effective for very long once the bottle is opened.

      Hope this answered your question.


  • Romina
    Posted at 08:28h, 26 March Reply

    When dilating drops are used on toddlers to examine eye properly, is it safe to do again the drops within a year or before please?

    • Randall V. Wong, M.D.
      Posted at 06:09h, 29 March Reply

      Sorry for the delay in getting back to you.

      Dilating drops should be safe for any healthy toddler. There are many situations where an infant, or toddler, needs to be dilated much more often than once per year. Sounds safe.

      Hope this was helpful.


  • karen
    Posted at 18:50h, 04 April Reply

    What are some of the diseases that cause the dialtion to take longer? Also, I know that the dialation drops work by incraesing epinehrine and noreinephrine and some block acetylocholine. What would happen if you already had too much epinehrine and noreinephrine in your eye and not enough acetylocholine. I have gotton my levels check and believe that my eye floaters and flashes are due too too much epinehrine and noreinephrine and perhaps fluctuating levels of acetylocholine. What is the risk of having your eyes dialated too many times?

    • Randall V. Wong, M.D.
      Posted at 08:49h, 07 April Reply

      I am not sure if your floaters are due to an imbalance of epinephrine or norepinephrine. There is no known risk to having your eye dilated too many times unless you have anatomical “narrow angles” and are at risk for this type of glaucoma. Your eye doctor should be able to determine this for you.

      The answer to your other question would be that too much epi/norepi might cause chronic dilation.

      I am not aware of any diseases, per se, that would cause longer dilation.

      Thanks for the great questions!


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  • jamie robinson
    Posted at 15:44h, 25 May Reply

    Hi Dr.I am 53 year old female and i think it’s about time for an eye exam. i get some weird thing when i exercise that causes wavy lines in the corners of my eyes, this is not new but oh so bothesome! it reminds me that maybe i should have an exam. my main problem is that i do have photo phobia seizures and anything that messes with my vision really sends me into a panic attack because when i have a photo phobia seizure i always get the aura first, so i’m doubly afraid of anything messing with my vision including these wavy squiggly lines similar to a migraine, so it’s really preventing me from doing a dialated eye exam. what options do i have? i live in colorado though.

    • Randall V. Wong, M.D.
      Posted at 16:34h, 25 May Reply

      I am wondering if you should first seek the help of a neurologist. Certainly, it is likely that someone needs to dilate you to figure out about your vision changes, but I am not sure I’d be to enthused if I new you were to have a seizure. Perhaps a neuorologist could offer a suggestion.

      It might also be possible to put you under anesthesia for examination. You might ask your doctor about the possibility of an “examination under anesthesia,” or, “EUA.”

      Best of luck,


  • Anne Lennox
    Posted at 14:28h, 10 September Reply

    I had an eye exam about 26 hours ago and my pupils are still dilated. I let the doctor’s office know about it, and they said to call back later today if my eyes are still dilated. It’s a Friday and I’m concerned that I won’t have any recourse until Monday. And of course I’m starting to be very worried that my eyesight is in danger of being damaged.
    Do you have any advice and/or reassurance

    • Randall V. Wong, M.D.
      Posted at 03:38h, 11 September Reply


      Not to worry, some of us are very sensitive to the drops and we can stay dilated much longer than usual. Also, the lighter the color of the eyes, the longer the drops will be effective.

      Sorry for the delay.


  • Lori
    Posted at 22:43h, 17 October Reply

    My 5 year old son has epilepsy and takes Trileptal twice daily for seizures. He sees a pediatric opthamologist every 6 months. Two visits ago, his eyes were dilated and he had a series of three seizures after the dilation, after which we had to give him Diastat to make them stop. He is going for his annual checkup this week, and I know that he is due for dilation, but I am very nervous. His neurologist said for us to try it one more time and see what happens. He wasn’t on the Trileptal at the time of the last dilation, so maybe it will make a difference. I am thinking of telling the opthamologist that I don’t want the dilation done until his next visit in June after he is done school, just in case he has seizures again, and I don’t want him to miss school after the visit. Is this OK to just postpone his dilation a few more months?

    • Randall V. Wong, M.D.
      Posted at 18:34h, 18 October Reply

      Dear Lori,

      I am going to defer to your pediatric ophthalmologist on this one, not knowing why he’s seen every six months.

      I wish you all the best with him.


  • Tiffany
    Posted at 14:11h, 06 November Reply

    Hello Dr. Wong,
    First, I’d like to thank you for having this site – what a relief to find. I have two unrelated questions for you.
    The immediate need is that I had my eyes dilated for a routine exam 24 hours ago, and they’re still HUGELY dilated. I do have light blue eyes, so I understand it should last longer, but when should I begin to be concerned? I’ve felt very disoriented since then (much like walking around with your glasses crooked all day). I had lasik 3 years ago (this was my routine follow-up). My left cornea is too thin to allow further correction (51 seconds of ablation, I was 20/850), my right is awfully close to that (46 seconds, 20/835). Could that be attributing to the dilation, and should I be concerned? I had gestational diabetes while I was pregnant but am extremely healthy now, and he said my exam looked great, really healthy. So, I know I probably don’t NEED to worry about this, but it is really disconcerting.
    The second question is something that has been bothering me since I was a child, and no one has had an answer (neurologist, eye doctors, etc.) or seemed alarmed. I see things with a sharp tint of pink out of one eye, and green out of the other. They equalize when both eyes are open, and if I have had my eyes open for a while, it’s not as severe, but if I’ve kept one or both eyes closed for an extended period of time (such as 30 seconds or longer), it’s quite pronounced. If I am awaking from sleep, it’s quite dramatic. What causes this?
    Thanks again!

    • Randall V. Wong, M.D.
      Posted at 08:37h, 08 November Reply


      Sorry for the delay. Blue/light colored eyes are more sensitive to the dilating drops, both dilating sooner and lasting longer. There really is no reason to be concerned. Also dilating drops last varying times, though most of us use the shorter lasting drops for office examination.

      Don’t think the ablation, nor gestational diabetes, is related to the prolonged dilation.

      Regarding the tinting of objects in your vision – can’t offer an opinion – symptoms are temporary and seem non progressive. My only guess is that often highly near-sighted people have a touch (very slight) amount of amblyopia.

      I’d ask your doctor to examine you and ask if there is any sign of this.

      All the best,


  • Jaye
    Posted at 08:28h, 22 December Reply

    I had an eye exam last week and for the first time the doc used those “undialating” drops. A day later I started having what I believe to be a vitrial tear in my right eye. Unlike the tear I had in my left eye a year ago, this one seems more violent and it seems suspicious that it happened right after my exam.
    Is there a chance that the undialating drops or something about the exam could have contributed to this tear?

    • Randall V. Wong, M.D.
      Posted at 18:35h, 22 December Reply

      Dear Jaye,

      Both dilating drops and “undilating” drops work by stimulating or inhibiting certain muscles of the iris. In my opinion, any changes in the retina or vitreous, such as a retinal tear (I am not sure what you meant by ‘vitrial tear’) would be nothing more than coincidental.

      Thus, I don’t think there is any chance of undilating drops contributing to a retinal tear.

      I hope this was what you were looking for,


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  • katheine
    Posted at 03:48h, 26 September Reply

    I would like to know how long does double vision last when blood work and mri and ct scan came back ok. What is the longest time .

    • Randall V. Wong, M.D.
      Posted at 23:27h, 27 September Reply

      Dear Katheine,

      There are many causes of double vision. Normal blood work, mri and ct are great news, but there can be other causes, such as problems with the nerves and muscles that move the eye.

      Therefore, it is difficult, if not impossible to say.

      I am sorry, but you may ask your doctor about the cause of the double vision…that may help me assist you.


  • Marie
    Posted at 03:14h, 14 October Reply


    my daughter has syndrome and the eye surgeon suggested that we test her vision every 3 to 6 months this time the doctor has requested dilating the pupils with Cyclogyl 0.5% eye drops, my daughter had a fit due to high fever in November last year after which she was put on diazepam only when she is having fever that it shoud be given to her for 3 days.

    is it safe to put these eye drops ? I’m so so worried about her and im trying to get as much as information as i can before i take her for the vision test.

    • Randall V. Wong, M.D.
      Posted at 10:46h, 15 October Reply

      Dear Marie,

      By “fit” do you mean seizure?

      I would ask your pediatrician about the drops, but I am not aware that they cause seizures.

      Best of luck to her!


  • Marie
    Posted at 03:29h, 14 October Reply

    sorry she has Blepheromosis syndrome –

  • Doris
    Posted at 16:20h, 29 November Reply

    2 weeks ago I had surgery in my right eye for a cataract & trabeculectomy for glaucoma. Dilating drops were used in the procedure. The pupil is still dilated in that eye. What are the possible reasons for this & what can be done?

    • Randall V. Wong, M.D.
      Posted at 08:58h, 06 December Reply

      Dear Doris,

      Obviously hard for me to “guess” what went on in your surgery, but let me see if I can answer you in this way. Many times during and after surgery, dilating drops are used to keep the pupil dilated after the operation. I use drops that will last several days and your doctor might have used drops that last longer. Also, sometimes the surgery itself may cause the pupil to remain dilated more than you’d expect.

      All the best.


  • Les
    Posted at 22:07h, 22 January Reply

    Dear doctor,
    I am 60 year old male and had dilated pupils 4 weeks ago for short duration. My eyes prior to that were always painful and gritty etc. Can dilating drops cause long lasting stinging and burning sensation in my eyes. It’s been 4 weeks. When I apply eye drops the stinging seems to go away. Is it only temporary condition as the eye doctor coulldn’t find anything wrong with my eyes except for its dryness.

    I’d appreciate your response.
    With regards,

    • Randall V. Wong, M.D.
      Posted at 09:42h, 01 February Reply

      Dear Les,

      Yes, dry eye can cause your symptoms, but I doubt it is related to dilating drops.

      I would encourage you to follow up with your doctor to relay the same comments regarding cessation of symptoms with the drops.


  • Cris Gregory
    Posted at 04:56h, 08 February Reply

    Dear doctor, i usualy go for a routine eye check every 3months because i have floaters, but the very first time i had a dilation test, my eyes remained dilated for over a day before things returned to normal. I am an african with brown eyes. I was realy scared and i think my doctor tried to reverse the dilation after the examination but it got worse till i was totally blind with a screaming headache throughout the period. Am worried bout my floaters although i am astigmatic, would you still advise me to have a dilation test? My last one was in january 2011….thank you

    • Randall V. Wong, M.D.
      Posted at 17:25h, 08 February Reply

      Dear Cris,

      Sounds unusual. Does your eye doctor want you to come back every 3 months?

      In my experience, patients’ undilate within hours. I’d give your doc another chance as your case seems very atypical.


  • Kymberli Pham
    Posted at 07:30h, 23 October Reply

    Hey Dr. Wong
    I brought my son to go get his routine eyes exam with a different doctor. The doctor part two drops of the dilating drop in my son eyes in between a 30 minutes time period and his eyes still not dilated on it own. I was told cause he have brown eyes. The doctor told me if it still don’t dilate the next day bring him back in for third set of drops. My questions to you is it safe to have all those in his eyes? And is it going to do damage to my son eyes? Thank you

    • Randall V. Wong, M.D.
      Posted at 07:32h, 24 October Reply

      Dear Kymberli,

      Sometimes dilation takes several applications of the drops. As I don’t know what drops your doctor is using, I can’t attest to the safety. You are right, in certain circumstances, dilating drops can be dangerous.


  • Marie Z
    Posted at 11:27h, 26 October Reply

    I have a bent retina in my right eye. My left eye is good so I see ok. My right eye omits letters when reading on TV or anywhere. The Retina Specialist said he could operate or just leave it alone, it was my choice. I opted to leave it alone for now. My regular eye doctor is concerned and has me coming in to check on my retina every three months. If my Retina doctor is not concerned, why is my regular doctor? I wonder if the drops I get every three months will make it worse.. I am 82 years old.

    • Randall V. Wong, M.D.
      Posted at 12:06h, 30 October Reply

      Dear Marie Z,

      Do you have an epiretinal membrane? This usually causes distortion and is a common finding that we, as retinal specialists, see often, but may be upsetting to a general eye doctor.


  • carrie diggs
    Posted at 20:27h, 14 December Reply

    My daughter’s eyes were dilated during a recent eye examination. The Dr did not tell me that she wad doing this. My daughter id ten; has had eyes examined before and her eyes were not dilated. Is this routine?

    • Randall V. Wong, M.D.
      Posted at 01:09h, 26 December Reply

      Dear Carrie,

      Dilating the eyes during the examination is valuable. Not only does it allow a more thorough examination, but it allows a better measurement for the need for glasses…especially in young kids.


  • Debbie
    Posted at 03:21h, 10 April Reply

    I have a bad panic disorder and suffer agoraphobia. I got diagnosed with a routine eye exam for glaucoma. I have never had my eyes dilated and am absolutely terrified to do so. Can my medical doctor give me a prescription to stop the panic I know I will have? Also will it take longer to come out of dilated eyes if I am panicking. It seems to me dilation and panic are the same symptoms except normally I can stop a panic attack and my eyes return to normal ,not bleary if I go home. I’ll have no way to escape the doctor induced eye dilation so how am I suppose to deal with this.
    any information would be very helpful

    • Randall V. Wong, M.D.
      Posted at 09:01h, 23 April Reply

      Dear Debbie,

      Hopefully you’ve successfully had the exam by now. If indeed you have a panic disorder, either your medical doctor or your psychiatrist should be helpful.


  • rahul
    Posted at 16:47h, 17 January Reply

    I had an eye dilation exam a month ago and after the eye dilation exam I got large eye floaters did the dilation eye drops cause this floaters

  • rahul
    Posted at 17:58h, 23 January Reply

    Then can you tell me the reason how did floaters appeared after an eye exam which include dilation of eyes an my floaters are very big the look big as a building do people have this kind of eye floaters which appeare very big

  • rahul
    Posted at 10:48h, 25 January Reply

    Can dilation cause floaters became before the exam I had medium size floaters and after the eye exam which include dilation of eyes I got large floaters is it normal to have large floaters because the floaters look big as a building if I look from a distance of 30 feet can you tell me if its normal because I got 10 large floaters after dilation

  • derrick
    Posted at 18:36h, 14 April Reply

    I had my first eye exam at 18 I was in need of glasses from playing the computer, I also was experiencing a cloud type floater that moves side to side on my eye or when I move down in a fairly quick movement reaction with the eye, slowly or while blinking seems to hide most of this affect, a year later I go in on a second exam for my eye’s because I was experiencing flashing while waking up in the morning in my right eye, everything was said to be fine. after the second exam I came home and few days later was having white-ish grid patterns while waking up from squinting my eye’s

    I also noticed later on waking up one day staring at a plain white wall black specks appearing then 1 second later disappearing this still happens however doesn’t seem to be as easy to see when i have on my glasses could these be floaters? just in a different manner? i also have a new thing that looks like small squiggly lines that don’t act like your typical floater as they don’t float rather follow a path move like flowing water all over the place and are see through.

    I’ve been worried about retina problems but for a while but just in my right eye and now both after my second exam, I’ve been to the eye doctor last year and about maybe a month and a half ago for my second with the same results them saying everything is okay.. total check ups (2).

    i also have experienced issue’s moving my eye’s with slight pain but i was sick a few months ago with a bad sinus infection, could that cause the problem? only thing is its been a while since i was sick and still have the it.

    first check up was okay, second was said to be okay but after was experiencing all the things listed above. should I go back for another after just having one about a month and a half ago?


    1 small squiggly lines clear see through

    2 black appearing and quickly disappearing specks in field of vision

    3 white-ish grid patterns while squinting or blinking when waking up in the morning ( thought I might’ve seen this before my second check up vaguely while blinking). so guess it’s okay?

    4 difficulty moving my eye’s – i move my eye’s a lot checking and focusing tending to stress myself and worry.

    Been worrying ever since my second eye exam what steps should i take? does it sound like i have anything, am i overreacting?

    Thanks for any helpful advice in advance.

    • Randall V. Wong, M.D.
      Posted at 09:51h, 20 April Reply


      I can’t really advise you since I’ve never examined you. I can only recommend that if you develop a lot of new floaters, squiggly or otherwise, an increase in the frequency of flashes or decreased vision, you should contact your eye doctor.

      I’m really limited.


  • Evan
    Posted at 18:48h, 15 August Reply


    Thanks for this article. I recently had an eye exam, and the dr. did not dilate my eyes. She said that my pupils are naturally large, so there was no need to dilate. I’m a bit concerned, as I have numerous floaters, including long chains of them, and she said she did not see any. Given that she was not able to see my floaters, I’m wondering if she was able to get a good enough view of my retina to ensure the health of my eyes. Is it normal not to dilate when the pupils are large?

    Thank you for your helpful advice.

    • Randall V. Wong, M.D.
      Posted at 17:29h, 17 August Reply


      In my experience, I’ve never been able to adequately examine someone’s retina without dilating drops….ever.

      On the other hand, and in my experience, I rarely see floaters in young individuals who complain of floaters…though I know they can see them.


  • bash
    Posted at 03:20h, 01 September Reply


    my wife had her eyes examined yesterday (brown eyes) and she had three eye dailiting drops 5min apart. after 24 hours her vision is very bad and worst of all she started to have double vision.

    please advice if having double vision after dialiting drops is normal?

    Many Thanks,


    • Randall V. Wong, M.D.
      Posted at 09:03h, 02 September Reply


      No, not normal, but it could be. Have to figure out the real cause of the double vision.

      She should consult her doctor at once.


    • Randall V. Wong, M.D.
      Posted at 09:04h, 02 September Reply


      Drops don’t cause double vision. I’d consult her doctor at once!


  • Dave M
    Posted at 16:44h, 14 November Reply

    I had a vitrectomy after suffering a detached retina. I was on dilating drops (and others) for 2 months after. Its now been 2 and 1/2 weeks after stopping the drops, and my eye is still dilated. Is this normal?

    • Mike Rosco
      Posted at 23:19h, 13 February Reply

      Hello Dave,

      Many docs use Atropine to keep the pupil dilated after surgery. The effects of Atropine can take longer than 2-3 weeks to wear off. Since it has been several months, would you be able to provide me an update? And I promise there won’t be such a delay this time around!

      Talk soon,

      Dr. Mike Rosco

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