It depends on who you talk to. Some people are worried about babies looking at any kind of screen - whether television or computer. The reason for this can according to Brillbaby (n.d.) be broken down into three main concerns: radiation, eye strain and attention span.
Radiation: Most modern home computers emit a negligible degree of radiation. If the radiation from the average computer were really harmful to babies, then it would be harmful to everyone, and we would all be told to stay away from the computer! However, the old cathode ray tube (CRT) monitors - the big, bulky kind - do emit a significant amount of potentially harmful radiation. People who are particularly sensitive to this type of radiation (estimated to be around 20 percent of the population) can suffer ill effects from prolonged exposure, with symptoms including low mood and decreased immune function. Thankfully, liquid crystal display (LCD) monitors - which do not have this problem - have become the norm in most countries. If you are using a CRT monitor with your computer, it is advisable to get an LCD monitor as soon as possible - for the sake of your health as much as your baby's.
Eyestrain: The degree to which computers provoke eye strain largely depends on the type of monitor. If you look closely at CRT monitors, you will see the screen flickering. Prolonged use of such monitors tends to cause eye strain. Thankfully, modern monitors have very high refresh rates and this problem has been reduced considerably. Many people who used to have eye-strain problems with CRT screens do not have problems with LCD or plasma screens.
Attention Span: Certain television programmes for babies rely on quick edits or the element of surprise (a person or puppet popping up suddenly). Some experts worry that very young children exposed to programmes with quick edits or too many surprises will be more susceptible to attention problems in later life. The concern was that this level of stimulation, which was unnatural, would condition the developing mind to view that as normal. Then by comparison the real world would be unsatisfying - it wouldn't be stimulating enough.
American Academy of Pediatrics n.d., American Academy of Pediatrics Announces New Recommendations for Children’s Media Use, viewed 17 October 2019, from http:// www.aap.org/en-us/about-the-aap/aap-press-room/Pages/American-Academy-of-Pediatrics-Announces-New-Recommendations-for-Childrens-Media-Use.aspx
Brillbaby n.d., Related Topics: Babies & Computers, viewed 17 October 2019, from http:// www.brillbaby.com/early-learning/related-topics/babies-and-television.php