For the past few years now I have been experiencing what seems like hypnagogic imagery during the day when my eyes are wide open. I have always thought it had something to do with dehydration, but recently I've been drinking alot of water and it has only been increasing in frequency. It is accompanied by a feeling of lightheadedness or dizziness and often occurs when I stand up after sitting or lying down. It is just dots(similar to what you see when you press your hands up to your eyes) and sometimes when it's more intense it seems to form a frame(like tunnel vision) around whatever I'm looking at.

Is this dehydration or something possibly psychologically wrong with me?