Why Do Contat Lense Irritates My Eyes So Much I Can Only Keep Them On For A Couple Of Hours?

I am 21 years. -2.25 left eye and -4.75 right eye (astigmatism in both eyes too, about -1.00). Perfectly health.
My friend told me he often forget he is wearing contact lense. That is just very surprising to me because my eyes feel irritated everytime i wear them. Anyone know what brand of contact lenses suit me the best?I heard contact for astigmatism is usually pretty irritating to eyes. Is that true?