Eye test drunkenness

October 22, 2005 12:10 PM

Would it skew the results of an eye exam to show up drunk?
posted by mr_crash_davis to health & fitness (17 comments total)

That might depend on how drunk your planning on being?

Alcohol can affect your vision by screwing up depth perception and things. I don't think it affects the physical working of your eyes so much as it confuses your brain into not being as good at interpreting all the different signals your eyes send back.
posted by alexst at 12:17 PM on October 22, 2005

Probably. It does involve decision making. I wouldn't recommend LSD, either. For completely different reasons.
posted by doctor_negative at 12:17 PM on October 22, 2005

How would one get to the eye exam? Drive drunk? Stagger on foot?
posted by Cranberry at 12:22 PM on October 22, 2005

I'm no cognitive scientist, but speaking from a lifetime experience with seeing things, and many years expertise in getting drunk, I would say absolutely it would. The effect might not be very noticeable after just a drink or two, but that's not what I call "drunk." If you're more than a few in, you will definitely have more trouble focusing.
posted by scarabic at 12:43 PM on October 22, 2005

A way that police are trained to recognize drunk people is by looking for horizontal gaze nystagmus, which in English is looking for jerkiness in eye movements as the subject tries to follow a moving object.

"Horizontal Gaze Nystagmus - Horizontal gaze nystagmus is an involuntary jerking of the eyeball which occurs naturally as the eyes gaze to the side. This test theorizes that when a person is impaired by alcohol, nystagmus is exaggerated, and that alcohol-impaired person will have difficulty smoothly tracking a moving object. To administer this test, an officer asks the suspect to watch a slowly moving object, such as a pen or small flashlight. As the officer moves the object horizontally (back and forth), the officer watches the suspect's eyes as they follow the object, watching for signs that (1) the eye cannot smoothly follow a moving object, (2) distinct jerking when the eye is at maximum deviation, and (c) an angle of onset of jerking within 45 degrees of center. The presence of four or more signs between a suspect's two eyes is considered to suggest unlawful intoxication. The circumstances of a roadside administration, or a lack of training for the officer administering the test, can significantly affect test results."
posted by jellicle at 1:17 PM on October 22, 2005

Assuming you are the patient, yes.

The "follow the pen" sobriety test works because your eye moves very irregularly when drunk. As such, I'd assume that the test would be compromised by booze-based nystagmus.
posted by I Love Tacos at 1:20 PM on October 22, 2005

on posting: I lose.
posted by I Love Tacos at 1:21 PM on October 22, 2005

The answer's yes; yes, nystagmus, but not just nystagmus. Drunk people suffer a decline in acuity from alcohol's direct effect on neurons.

If someone was seriously considering showing up to an eye exam drunk, someone needs to get into an alcohol treatment program fast.
posted by ikkyu2 at 1:44 PM on October 22, 2005

Alcohol would relax the muscles that make the eyes track together, so it could cause a sort of amblyopia. If you have enough experience with alcohol that your brain circuits are compensating it out, I would suspect you need to be evaluated for ingesting a metric buttload of booze, far too often.
posted by deep_cover at 3:24 PM on October 22, 2005

"How would one get to the eye exam? Drive drunk? Stagger on foot?"

Assume the subject has a sober driver to ferry him back and forth.
posted by mr_crash_davis at 4:14 PM on October 22, 2005

What if you're already amblyopic (from birth)?
posted by matildaben at 5:25 PM on October 22, 2005

matildaben, there was a discussion of this before in another thread I have not the time to look up. There's a segment of the population that due to medication or other illnesses (I do not know if lazy eye is one of them) will not pass the the horizontal gaze eye test. There was a little debate as many people were sure that the police could tell the difference between a drunk person and a person exhibiting a false test from other causes. I contended (and I had cops tell me) that that indeed they have seen people unable to fail the test who were no drunk and they could not tell a difference. I would imagine someone very trained could tell the difference, but that's just academic. The average cop at night, on duty, will not be able to tell the difference. That said it's a rarity to be unable to pass this but there's a reason why other field sobriety tests are given.

And I don't think an eye exam would be skewed if the practitioner knew you were drunk. The dialation of the eye changes as does reaction to stimuli. The question is what they are testing for in an eye exam.
posted by geoff. at 8:47 PM on October 22, 2005

I needed more contacts.

I called LensCrafters but they said I would have to come in for an eye exam just to make sure my eyes were healthy and stuff. I got off work at was home by 5:20 before walking the three blocks to the 6:00PM appointment. Since I was ahead of schedule, I stopped off at the bar that I worked part-time at and ended up have a couple, (three?), kamikazes before hoofing over to the appointment.

Once at the office I was surprised to find it was a full eye exam including the 'rest your chin here and click this everytime you see a light blink' test. I then saw the doc who after going through the chart and her series of 'better now or now?' lens checking declared that my vision had improved.

YMMV.
posted by geekyguy at 10:00 PM on October 22, 2005

I'm glad you cleared that up, we did not know from the question that this was over.
It sounded as though this were an upcoming event, and you were planning to get drunk to celebrate in advance or something. I, at least, was confused.
posted by deep_cover at 9:08 AM on October 23, 2005

You're still confused. Check the posters' names.
posted by languagehat at 11:33 AM on October 23, 2005

Actually, as I think more on this, there are other factors than alcohol's direct effect on neurons at play.

Alcohol would relax the muscles that make the eyes track together, so it could cause a sort of amblyopia.

Not pertinent - when was the last time your visual acuity was tested in both eyes at the same time? Never, I wit, unless someone made you grab at the wings on a Titmus Fly Stereogram.

However, there are muscles within the eye. One of them tenses the lens and helps you focus. Alcohol causes problems with muscular coordination and is a muscle relaxant; I imagine that applies to this little muscle as well. In addition, there's a muscle that operates the iris; I think it's called the ciliary muscle or something like that, and it could be similarly affected.

Also, alcohol can be very dehydrating. Visual acuity changes with changes in hydration because the shape of the eyeball (and maybe the lens) changes; you can get far more dehydrated by drinking alcohol than could be achieved under normal physiologic conditions.
posted by ikkyu2 at 12:04 PM on October 23, 2005

languagehat: You're right, my bad. I did not go back to the original question and check the poster.

ikkyu2: I'm sure that's all true. They usually don't look at both eyes at the same time, although I was guessing having temporary amblyopia could cause strange things at the eye doctor's, which they might notice. I was basing that statement on someone I used to know, who was badly cross-eyed only when he drank, and that was the explanation his eye doctor offered.

I have monocular diplopia (two images in each eye) only late in the day when my eyes dry out from staring at a computer too long, and my eye doctor said it was insignificant. I become cross-eyed from certain pain meds that are also muscle relaxants, also often late in the day.

It's only noticeable at certain focal distances, around 20 to 40 feet maybe, and I have had this for so long and it had come on so gradually I seem to be able to compensate it out with some sort of brain thing. I apologize to anyone I may have offended by under-explaining for the sake of brevity. I was visualizing someone without a lot of practice at this sort of thing, possibly showing up at the eye doctor's office with suddenly and unexpectedly, having 4 images to choose from, 2 from having his focal muscles relaxed and 2 from dehydradation, and having his doctor wonder if he had something ghastly. (It's my understanding that monocular diplopia is most likely caused by something awful.)

I also have two different size pupils, apparently developmental (what's the word meaning "born with"?, that's the one I want really), and I always have to explain to neurologists that they have always been this way, lest they start looking for something much more interesting than just goofed-up pupils.

It's true that the eyes are the window to the soul, and a good eye doctor would spot absolutely anything out of the ordinary, whether it had to do with the visual acuity of an individual eye taken in isolation or not.

I would feel really badly if this person ended up having a lot of expensive tests hunting for a brain tumor, if in fact, he was simply drunk and dehydrated when he happened to stop by for an exam.

I meant well, I just didn't explain as fully as perhaps I should have.
posted by deep_cover at 2:25 PM on October 23, 2005