As far as I remember, American Academy of Pediatrics recommends the parents to avoid showing TV to their kids until two years old. As for educational videos, there are a lot more videos that just claim to be educational, like Baby Einsteins: Baby Einstein videos harmful for kids?

There is even an article in Time magazine that links early TV watching to autism: Does Watching TV Cause Autism?

I don't know how much this particular research can be trusted, since my friend with a PHD in psychology just has been attending a seminar on autism, which stated that the scientific community believes that autism is a purely genetic disease, and all other "findings" are just scandalous ways to get public attention.

Yet, I think it is better to be safe, then sorry. There is a great deal of material linking ADHD, poor school performance, delayed development, etc. with TV watching:

• American Academy of Pediatrics: TV and Toddlers
• White Dot: It's Official: TV Linked to Attention Deficit
• American Academy of Pediatrics: Passive Exposure to TV Linked to Sleep Problems in Children by Ruth A. Etzel, MD, PhD, FAAP
• CNN: Children And TV Violence
• Compaing for a commercial free childhood
• American Academy of Pediatrics: At Harvard University two researchers say that how much TV your kids watch affects how much they weigh.
• Does Background TV Make Kids Lose Focus? (7/30/2008)
• Kids and Violent Movies: A Scary Trend (8/27/2008)

As for the computer - it is just another TV screen. Besides, it is a TV screen that is quite close. And as you can see from the articles, it is not even the radiation that is the major problem, but the 2D format of presentation (TV is not really 3D as it seems) to the children and how it can affect the development of brain cells.

So... I think everything has to be taken with a grain of salt. You always weigh the risks and the benefits. For ourselves, we limited TV (or rather DVD, since our TV is not hooked up to any channels) usage only for long car trips, since my son hated the car rides. I thought it was better for him to enjoy some educational DVD then scream the whole way through. There are plenty of very good educational DVDs, you can find the most recommended ones here: http://www.childandme.com/teach-your-child-read-multimedia#dvd

As for the computer, since we didn't watch ANY TV during the day, AND my son didn't like the flash cards (and we moved onto phrases, so it was more and more difficult to retain his attention), around 18 months we introduced a computer. I'd sit him on my lap and for the next 5 minutes we'd watch 10 presentations one after another, some starfall.com... and it worked great for us! I figured that 15 mintues a day of screen time on a weekday and one DVD in a month on a weekend - can't do that much damage. Now I show less presentations (about 5-6), and let him play at starfall.com a little longer, by himself, though - just once a day, or once in a few days. At two and a half, is he really good with a regular mouse, navigating anywhere he pleases. There is a list of other good websites here, http://www.childandme.com/teach-your-child-read-multimedia#web
Honestly, at two and a half I didn't find anything other then starfall, that I thought was worth spending the time in front of the computer. I think the other sites are geared at a little older kids. I might be wrong - many people delightfully use them.

Now, at 2 1/2 I started showing him some DVDs quite regularly: I think he is much older now, so twice a week (usually on weekends, when he doesn't see the computer anyway) is OK. And my husband, who gets up early with him, and lets me sleep a bit late on weekends, is very grateful for a morning break as well.

Even now, when I was searching for a daycare for my son, one of my first questions was if kids are shown TV. If there was even a hint of positive answer, that daycare was off my list permanently. I'd rather chose myself how to use the screen time, what to watch and how to limit it.

This is just another personal view on the issue. You would have to decide for yourself, and most probably it would depend on how much you, personally, watch TV. As I said, ours isn't even hooked up to anything but a DVD player, so we occasionally enjoy a DVD with my husband on a weekend. It is easy to have TV limiting rules if they apply to ourselves, not just the kids. I have a friend whose TV is always turned on. Just for a background. So her daughter was very good with a TV control before she could crawl, and is watching a tremendous amount of cartoons, TV programs, etc. While I wouldn't be thrilled about such situation, my friend just laughs: "How can we limit it if we, ourselves, can't live without a TV"? So, your own TV habits are probably going to be the biggest deciding factor.

What do you think? Please share your opinion in the comments below.