One kind of blindness is a perverse refusal to accept reality or to accept our need to change in response to reality as it is. Many of us will find ourselves becoming aware of that wilful kind of blindness as we try to confront the reality of God in prayer.
But our literal physical sight can be a helpful part of prayer. It may well be sensible to counsel small children to 'shut their eyes' to pray, thereby making it less likely that little Johnny will kick Peter during assembly, but it seems a strange idea of God if we can only regard the world he has created as a distraction from prayer. Far better to use our God-given sight as an aid to prayer. Remember words (with which Christians are so easily obsessed) are one removed from reality whereas what we see is likely to be nearer to reality itself.
In the use of our eyes, as in so much else in prayer, we are brought up against our frequent inability to stop and stare and wonder - to take time. There is enough beauty in a single flower, a single piece of pottery, the shape of a tree, or a single good Christmas card to provide us with enough material for a whole prayer session.
Again, some find the use of sight, or sight with imagination, more helpful than others, but if we largely go through life with our eyes closed, it will enlarge our understanding of God if we sometimes try to 'pray with our eyes open'.
God looked on all that He had made and it was very good
If God took the time to look at it so should we... and we too shall discover that it is very good.