Chris1234, My DS7 is doing vision therapy too... He started in the summer when he was 6. It has been wonderful! But I do hear you on fitting stuff in. My DS doesn't even do that much extracurricular but he needs a lot of down time/alone time - where he plays imaginary games on his own. I cut a lot of activities for awhile - his OT and VT are so important. He is doing an indoor soccer clinic right now (it's only once a week on mondays) and in Feburary he will be in an after-school art club - so it may be gettign too hectic, we'll see.
What helps: (1) I have his VT and OT scheduled for Saturdays now, which makes a huge difference. DH just left with him for OT - then they will go to eat and go to the hobby shop and then go on to VT. The other thing that helps is I got a computer program for at-home exercises. That helps because he likes the games of the prgram and each exercise is only 7 minutes. Other than that it is definitely a challenge.