what i mean by 'mechanical' ...

[mel07green]

I mentioned in a previous post a few reasons why I think the symptom i am experiencing (large grey streak in vision) is localized to the eye itself and not neurological. I would very uch like your opinion on this ...
Firstly, the symptom is in one eye only
Secondly, it appears much more clearly defiined and darker (ie black instead of grey) when I close one eye and squint really hard.
The same thing happens when I push gently against me eye in the mirror OPPOSITE of where the symptom occurs in my visual field.

COULD this be a type of pressure phosphene caused by changes in the vitreous or tugging.
NOTHING was observed by the opthalmologist except the peripheral retinal scar ....

[curtis221]

I have the exact same thing you have. Mine happens when I blink sometimes , but mainly in front of a computer or in dim light. Never outside in bright light. Let me know if there is anything that can be done. Or why this happened all at once.

[mel07green]

hmm, well it's definitely dark (like the spot that appears when you look to your extreme left or right) ... but it does kind of "flash" brighter momentarily when i blink ... all i know is that the specialist looked at my retinas and noticed nothing abnormal ...

[Ag-i-doc]

if that is what you are experiencing, then yes: those are totally benign.

but i am not 100% sure thats what you're seeing.  *most* phosphene sensations are "lights" not a "dark spot"...

[mel07green]

i'm sorry, i've course you can't say that without having seen me ... could you perhaps tell me though whether pressure phosphenes are benign?

[Ag-i-doc]

??

[mel07green]

ok, let me rephrase that ... i'm not asking you what caused mine, just for some possible generic causes for such a phenomenon ... i mean, if it IS a phosphene of some sort, then something must have caused it, right? i'm puzzled as to why something like this would just "happen" ... (unless of course it's not a phosphene and i am back to square one)

[Ag-i-doc]

i dont know.  i cant tell you that you are fine...i wish i could!  i have never seen your retina.

[mel07green]

no problem ... i really appreciate your input ... can i ask one more thing ... if this serious retinal stuff has been pretty much ruled out, should i just stop worrying?

[Ag-i-doc]

i'm sorry.  i meant to say "i dont know" what could cause that.  i was just a little lazy and put the two question marks :)

[mel07green]

it's there all the time, though, just more noticeable under those circumstances i mentioned. what could have caused it?

[Ag-i-doc]

i should have said any "visual sensation" that is repeatable and only occurs under those curcumstances...

[mel07green]

it's not actually a "light" - it's grey/black - and it's there all the time, though most noticeable when i do those things i mentioned above.

what would cause such a thing??

[Ag-i-doc]

that definitely *is* a pressure phosphene.  any light or flash that you ONLY see when pressing on your eye...thats a pressure phosphene.  any light that is repeatable and you ONLY see when performing any particular event (looking R or L or squinting or whatever) is a pressure phosphene.