Anybody got/heard of umbropsia?

Been scratching my head as to how I managed to pass a recent VEP when on the second test run after just a few seconds the checker pattern on screen faded completely out to a uniform pale grey background, remaining like so for the rest of the test, although the yellow focus square remained visible bobbing at the centre, but ragged rather than square. I mentioned it to the tester, the neuro and to an eye consultant,  but neither of them recognised this effect, so I have tried to investigate myself and came across a reference to something called 'umbropsia'. Looks like a rarely used word because Google is convinced I must mean 'ambrosia'! and there are very few hits. From what I can find, umbropsia is described as  asymptom of  fading out or brightening up of vision (or alternation of), when staring at a fixed point as in a VEP. Its manifestation is described as paroxysmal, which I think means it can come on suddenly for a short period in a clinical setting under the right circumstances. If anybody knows what it means in a clinical context please enlighten me. One factor thought relevant to its triggering appears to be related to stimulus frequency, if i understand correctly,  which I think might be relevant to the speed of cycling through (Hz) the checker pattern. Any thoughts?

What I can see is its is also called "

Temporary chromatopsia and alternate umbropsia" It is also associated with remittent MS.



Oooops I couldnt get the letters to go smaller.

Hi I had the same thing but passed the VEP with flying colours which I found very strange hello

Hi I had the same thing but passed the VEP with flying colours which I found very strange hello

Thanks Jellybean, those are seperate but possibly closely associated symptoms. The first I think refers to reduction in colour perception.

Scrappydoo21 can I ask for some further information: Are you diagnosed? Did you report your experience and get any feedback on it from anybody? Did they know what it was? Was it on all tests on the affected eye, or both eyes, and how quickly did it start. Did it endure for the rest of the test, or alternate between fading and brightening? Have you noticed it outside the VEP setting?


Thanks guys

I passed me VER test,however looking at the screen the checker board just faded into a blurr to me and a greyish colour.I cannot focus well on things.

You mean your focus made it indistinct as opposed to contrast fading out?

Hi MRBobowen

Finally found the post yay..................but no good news Im afraid yes I am diagnosed with MS for about two years now I have four of five fluffy clouds (lesions) in the brain, I did mention this to the nurse, the gp, the neuro in short everyone I could think off but he reply I got back was your VEPS were clear, although I do have colour de-saturation in my left eye which has never cleared from the optic neuritis I have had multiple bouts of this, for me after a few seconds the checker board faded to just a grey smudgy thing although the yellow square kind of remained but it was no longer a square it felt distorted it was worse on my left eye the one that has been most affected by ON the nurse ran the test five times eventually i called a halt because it was starting to hurt I hope this helps.

That is really interesting; it sounds identical to my experience, except that the test was not done again. I wonder if you also have been seeing circular or ring shaped phosphenes as this is something else I cant get anybody to recognise.

no but I do see zig zaggy lines, should say my ms was diagnosed quite quickly with positive lp, not a nice experience and a mri if you can find anything else to do with this please let me know Thanks

Yes I get those occasionally. Seems we both got told the VEP was normal, but as a matter of fact I was able to get a quick glance in my hospital notes today (I was obliged to act as courier ferrying the file between departments) and for the VEP I saw that it was on the very edge of being passed normal. The speed for the left eye was 107 and the right eye 98 and alongside was a note saying it is at the top point of the high end of being normal for 'differential in eye speed'. Also the neuro makes an admission that he is puzzled by the effect I described on the VEP; especially given this borderline result. Wht dont they say this to your face, just told me it was normal! Oh by the way Scrappydoo21 the link below was where I found the first reference to it - number 2/8 in the listed case summaries:

Some good news, yesterday I got a phone message asking me to make a hospital appointment today at 4pm (can you believe it on the day when docs are supposed to be on industrial action). When I arrived the guy I saw the week before said in discussing my case with colleagues, he had decided to send me for a further MRI but this time just looking at at the vision part of the brain and also he was referring me to Moorfield Eye Hospital to see a well known neuroopthamologist. When I asked , he said he had never heard of umbropsia though! I guess we should bear in mind that even the experts dont know it all. I also think its worth remembering for someone undiagnosed, that when there are eye issues and they draw a blank with the neuro, they might still be able to make headway through the eye specialists. 

For reference, the mean speed for the P100 wave component on a VEP for someone under 60 is around 100 milliseconds with a. normal maximum of 110 msec. A speed diiference between each eye of more than 10 msec is considered grossly abnormal, and a normal eye differential is expected to be below 5 - 6 msecs. The P100 number increases as nerve conduction speed falls in the presence of damage on the nerve pathway. People over 60 could be within normal range up to 120 msec female, 125 male.


Source: see slide 8 of this slideshow:

Oops I mean slide 10