Dear
Welcome to HCM
We understand your concerns
I went through your details. 4 month old child is yet to focus. The
visual system of a newborn infant takes some time to develop. In the first week of life, babies don't see much detail. Their first view of the world is indistinct and only in shades of gray. It takes several months for your child's vision to develop fully.
Usually an infant is able to focus around the period of 3 to 4 months, many delays are reported. To help stimulate your 2- to 3-month-old child's vision development, try these:
1. Add new items to their room or frequently change the location of their crib or existing items in the room.
2. Talk to your baby as you walk around the room.
3. Keep a night light on to provide visual stimulation when they are awake in their crib.
If you require more of my help in this aspect, please use this URL. http://goo.gl/aYW2pR. Make sure that you include every minute details possible.
Hope this answers your query. Available for further clarifications.
Good luck. Take care.