Problems getting 18 mth old to wear glasses & patches

My son has  been treated for strabismus and formerly nystigma since around July 2007.  So far he has worn patches on alternate eyes and had one botox treatment last year (after which the nystigma disappeared). Since the botox the strabismus is greatly improved as both eyes now move together.  However the majority of the time my son now looks from a sideways position if this makes sense. At the last appointment he was also prescribed glasses.  He is currently 18 months old.

Since this point things have been very difficult.  I have found it impossible to get Zach to wear the glasses and have tried everything I can think of,:

Playing a game to encourage him
Wearing my own glasses
Putting his glasses on me
Forcefully putting them on and restraining him
Distracting him after putting them on
Telling him off
Getting someone else to try him

However nothing seems to work and it has got to the stage now where i either end up crying or getting angry with him and shouting at him neither of which helps any.  At one stage a friend of mine got him to wear them  as we both distracted him, then on the second day he had a little fall and his glasses were a little loose afterwards.  Even though I had them fixed he still refuses to wear them, either throwing them aside as soon as he is free or throwing himself about if I'm holding him.  

Now what really concerns me is that he has started to pull off his patches constantly too, I think because he now hates anything to do with his eyes so I am worried that he is not getting any benefit from his treatment. I just keep putting his patch back on and firmly telling him no but he still pulls it off again 5 minutes later (and brings it back to me!) It is so difficult because at the moment he is just that little bit too young to reason with as he doesn't understand why.

Can you advise on how I should approach this and the likely effects of the above.  I am worried that his eyes are going to get worse or be untreatable at this rate