# One drop in left eye. **URL:** \ **Category:** Factual Questions\ **Created:** [September 29, 2002, 4:52am UTC](https://boards.straightdope.com/t/one-drop-in-left-eye/130072 "2002-09-29T04:52:40Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [September 29, 2002, 4:52am UTC](https://boards.straightdope.com/t/one-drop-in-left-eye/130072/1 "2002-09-29T04:52:40Z")
I have to put meds in my eye three times a day (glaucoma), and am wondering just how precise a dosage “one drop” is. Given the physics (size of hole and specific gravity of solution), I’d guess it to be pretty precise. But does how hard I squeeze alter that any? Dosage probably isn’t important anyway in that much of the medication runs down my cheek. Just curious. 🙂 Peace, mangeorge ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [September 29, 2002, 5:02am UTC](https://boards.straightdope.com/t/one-drop-in-left-eye/130072/2 "2002-09-29T05:02:37Z")
Well, eyedrops are tested for dose size during development and clinical testing, but it’s always a bit more variable than we would like. For one thing, the angle at which you hold the bottle is extremely important, and no one gives instructions about this. There’s also foam, and pressure, and temperature, and… you get the picture. Fortunately, the amount of drug delivered depends, most of all, on the volume of solution that can be held in the little pocket between the eyeball and the lower lid–and that’s usually less than a drop. ---
**Author:** ![Violet](https://avatars.discourse-cdn.com/v4/letter/v/ebca7d/32.png) [@Violet](https://boards.straightdope.com/u/Violet)\ **Post date:** [September 29, 2002, 5:16am UTC](https://boards.straightdope.com/t/one-drop-in-left-eye/130072/3 "2002-09-29T05:16:58Z")
If a stream comes out, then you squeezed too hard. ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [September 29, 2002, 5:19am UTC](https://boards.straightdope.com/t/one-drop-in-left-eye/130072/4 "2002-09-29T05:19:41Z")
Yep, just like a zit. ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [September 29, 2002, 5:24am UTC](https://boards.straightdope.com/t/one-drop-in-left-eye/130072/5 "2002-09-29T05:24:41Z")
Judging from the fact that the “wettability” factor in your eye probably couldn’t be any greater, my uninformed guess would be that simple contact (a fluid sweep) across your eye would happen (and according to the manufacturer - be sufficient!) regardless of if you apply one drop or two. Since one will work, conserve your med. ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [September 29, 2002, 5:36am UTC](https://boards.straightdope.com/t/one-drop-in-left-eye/130072/6 "2002-09-29T05:36:05Z")
Thanks, **Nametag** , for the _serious_ answer. **Violet** and **lieu** ; 😛 Actually my doctor demonstrated exactly how to administer the drops. She’s quite young and _very_ professional. I like her. 🙂 Peace, mangeorge ---
**Author:** ![EmbarrassingDad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/embarrassingdad/32/5441_2.png) [@EmbarrassingDad](https://boards.straightdope.com/u/EmbarrassingDad)\ **Post date:** [September 29, 2002, 12:26pm UTC](https://boards.straightdope.com/t/one-drop-in-left-eye/130072/7 "2002-09-29T12:26:48Z")
Well, with an occasional severe hangover, I can state that when my hands shake, it’s pretty obivous I’m getting a “light” dosage. The drop wouldn’t haven’t dripped without severe agitation. ---
**Author:** ![EmbarrassingDad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/embarrassingdad/32/5441_2.png) [@EmbarrassingDad](https://boards.straightdope.com/u/EmbarrassingDad)\ **Post date:** [September 29, 2002, 12:28pm UTC](https://boards.straightdope.com/t/one-drop-in-left-eye/130072/8 "2002-09-29T12:28:25Z")
grrr this being one of those moments… obivous=obvious ---
**Author:** ![PosterChild](https://avatars.discourse-cdn.com/v4/letter/p/e274bd/32.png) [@PosterChild](https://boards.straightdope.com/u/PosterChild)\ **Post date:** [September 29, 2002, 5:05pm UTC](https://boards.straightdope.com/t/one-drop-in-left-eye/130072/9 "2002-09-29T17:05:15Z")
Back in my lab days, there were products that used drops as measurements. I forget how much volume they were supposed to be, but it was consistantly close enough to use with pipetted volumes. PC