If the congenital cataract is slight and won't affect his vision, there is no need for treatment. If it is serious, it is better to have cataract surgery at an early age and 1 year old is the right time. To prevent lazy eyes and strabismus in the future, he would have intraocular lens at 2 year old to correct his vision.
If your baby has congenital cataract, cataract surgery may need to be performed as soon as possible to ensure that vision is clear enough and won't interfere normal development of your baby's vision system. Some experts say it is the best time to perform surgery between the age of six weeks and three months. You can talk to your eye surgeon about timing of cataract surgery .
You'd better take your child to hospital and have a careful check. If congenital cataract affects his vision significantly, surgery should be taked as soon as possible. Some surgeons will put intraocular lenses in his eyes to correct the vision. While some other surgeons are hesitate to do it because the eyeball of children under 1 year old grow rapidly and it may reject the lens. So you should consult the surgeon.