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Thanks for posting your query.
I am Dr.Ratnakar and I am pleased to assist you.
If you have questions after reading my answer, be sure to let me know.
You have mentioned that your son is 5 months old. At this age he will be interested in looking at bright things and so obviously he looks at the laptop screen though he may not be actually watching the videos.
Since he is too young to understand or read anything on the laptop, he may not be constantly watching it with out blinking. So the strain put on the eyes is very less.
So my answer to your question is it will not affect his eyes.
Regarding the head remaining steady, complete steadiness occurs at around 5 months of age. Once the head becomes completely steady , the baby starts rolling over
I hope that answers your question.
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