Hi Magaret,
My GP has been trying to push statins on me for years, and my cholesterol isn't even high (my last reading was 3.8).
I can understand why your son is reluctant to take them. I can also understand, though, why this might worry you!
As far as I I see, your son has three option:
1) Accept his cholesterol is high and take the tablets.
2) Accept his cholesterol is high but try and lower it himself using diet etc. Give it six months and then retest.
3) Carry on as normal and risk causing further damage to his eyes.
Whatever decision he makes, it has to be his. From the sounds of it, he is against takin the tablets, so maybe suggest option 2 to him?
Good luck! Em