Geometric grids in vision upon waking

[ahappymom2]

About a week ago I woke up in the middle of the night and there was a very strange geometric grid pattern in my entire field of vision in both eyes (linking octagon or rectangle shapes).  I sat up and in a few minutes it went away.  I fell back to sleep and woke again to find the same pattern in my site.  Again, I sat up and it went away in a few minutes.  This has now been going on for a week and happens every time I wake during the night.  I am now waking many times during the night to see this geometrical grid pattern and cannot get into a deep sleep like I am used to.  This only happens at night upon waking and my vision seems to be fine during the day.  I have had floaters and flashers for several years now.  I purchased a blood pressure monitor yesterday to see what my pressure and heart rates were.  My daytime readings have been in the 90/60 range with a heart rate of 60-65 and 90/60 range with a heart rate in the low 50’s during the night.  I don’t ever remember having blood pressures and heart rates this low when I have been checked at the Dr’s office so I am curious to know if this is related to low blood pressure and heart rate or if it is the sign of an on coming eye problem?  I am a very small female 5' 1" and 103lbs and do not exercise vigorously, just yoga and walking hear and there.  I also eat very healthy.  I am so confused and was hoping you could help.  Any info you can give will be greatly appreciated.  Thank you.

[ahappymom2]

I see the same pattern when I my eyes are shut or open and I sleep in the dark (no light).  I usually just watch tv for a short time before going to bed and I have never had a migraine headache.  I have had a few ocular migraines.  Thank you so much for your help!  

[Michael J Kutryb, MD]

The fact that it never happens in the day may be a good sign.  Do you see the grid pattern even in the dark or with your eyes closed?  Do you have some sort of light on in your room while you sleep?  Do you  use your eyes extensively for some task right before bed?  Do you have a history of migraines?  I have also read of a phenomenon called phosphenes or pressure phosphenes and even saw one mention of low blood pressure as a cause.  The grid pattern is vey suggestive of phosphenes but the cause in your case is unclear.  Perhaps this phenomenon has been happening for a long time - but you never sat up in bed in the middle of the night to observe.  Best bet is to get a good eye exam with your ophthalmologist and have your primary care doctor recheck things as well.  I wish you well.
Michael Kutryb, MD