is my kitten blind? need to know before give-away

Question
PAST: at 2 weeks old i noticed a large bruise between his eyes.  he looked as though he wasn't going to make it.  after a day and a night of constant care, the queen accepted him again, and he returned to 'normal'(?)
SYMPTOMS at 4-5 weeks:
*seems to follow sound or scent rather than objects.
*can navigate most areas, but bumps into light coloured or small objects, and falls down low steps. also tends to walk or fast-falk rather than run
*also, he seems to like two places away from the nest, but won't venture further on his own, whereas his sisters are tearing around the whole house at a million miles an hour!
*can not find food quickly when moved away from him
*panics when lifted (meows and wiggles)and calms down only when he finds his mother, sisters, or food dish
*his pupils dilate a little, but not as much as his sisters.
THE REALLY WORRYING SYMPTOMS:
*falls onto his back and his iris almost completely closes; and rhythmic 'screams' for about 10 seconds before clawing at his eyes and then eating his paw.  totally un-responsive during these occasional episodes (started on day of bruise at 3-5 a day, now reduced to about one every third day or so)
ON THE PLUS SIDE: he is loving kitten milk and kitten food from a saucer, and is quite active; and seems to be otherwise healthy, and is developing in other areas faster than his sisters (walking without wobbles, weening,

Answer
This is not a question that can be answered in here. A veterinarian would need to do some tests in person on a cat like this as well as look into the eye chamber with an opthalmascope, or an instrument with a light to see into the chamber at the retina.
One thing I do want to mention how ever is that when you charge a $10 or $20 fee for your kittens, people are more likely to actually take care of them then they are for a kitten they get for free.
It's all about 'perceived value.' Try it and see how much more willing they are to vaccinate and care for these kittens.
I hope you will be getting the mother spayed as soon as possible.
If your kitten is blind what will you do with him?