Originally posted by The man who was death:
sometimes u walk and walk and then without knowing, u bump into a lamp post. it's like u didn't see the lamp post there, so that line of vision coincide with the eyes' blind spot.
sec biology got teach this
i dun think tat is due to blind spot. yes it is true tat there is a blind spot in e eye where there is no photoreceptors at e spot, and nerve cells send signals from the photorecptors to the brain...
blind spot will be automatically made up by ur eyes...each blind spot in each eye is different. therefore wat e blind spot is missing in e left eye will b made up by the right eye.
i wld tend to say tat u would bump into a lamp post is not due to blind spot, but cos of attention deficit...
green spots occur as negative after images....eg, if u came across tis famous illusion in sleepy hollow, where johnny depp was playing w tis toy. two strings attached to a cardboard, on e cardboard, one side its a bird, e other is a cage..as he twists e toy, e bird seem to appear in e cage.
e image carries over to e next scene...tis has to b fast, as e images can diappear...green spots is due too looking at purple for too long, once e pruple colour disappear, a green colour will appear although there is no colour there...
e purple dots will disappear due to mainly two reasons. one, ur eye cells are fatigue, they no longer send signals to e brain (too used to the purple colour) however, if u move ur eyes, e cells will receive new signals, so, will still condt to see e purple colour...the other is due to the fact tat ur attention is on the cross..the dots will disappear..
