Asbeau: This might be an unpopular opinion but honestly, I think he's a bit too young. I'd read with him or take him outside or play with his toys alongside him instead. He has his whole life to be stuck in front of a screen.
While going outside etc. is also important, I don't expect toddlers to spend all their waking time outside, especially here in Finland during autumn and winter. They would die out there in the middle of winter. One can let their toddlers and young children to do both: go outside, and play videogames with their parents.
That said, apparently it IS important for kids to play outside too. At least here it was just in the newspapers that according to some new studies, lots of people all over the world become nearsighted because they read or watch small screens nearby too much as small kids. It was even predicted that in the future most people, already in their 20s or so, will be nearsighted and need glasses. (The common example used is how awfully many nearsighted people there seem to be in China nowadays, it seems as if all university students in China are wearing glasses for nearsightedness).
The current theory is that if a kid has to sharpen their vision near lots and lots every day (be it reading too many books or staring at a phone or tablet near them for hours and hours), their body tries to compensate to that by starting to GROW the eyeballs so that they become longer, which in itself causes nearsightedness (and certain other potential problems to the retina etc.). :-O
So all those teen comedies which depict nerds always having glasses were right after all: the nerds need glasses BECAUSE they read so much as kids, while the sportjocks don't become nearsighted because they stare at distant objects outside like the football and girls on the bench. It was also surmised that the sunlight might prevent nearsightedness.
If there is any truth to those findings, I now feel bad whenever I see kids staring at tiny phones near their face. And all this VR frenzy, putting VR goggles right in front of your eyes, will make it even worse.
I guess I am "lucky" in that sense because I've always been rather the opposite, ie. long-sighted, just like my father. Apparently my eyeball is shorter than normal, so I haven't become shortsighted even though I played lots of computer games already as a kid. On the downside, I tend to need reading glasses nowadays if I want to read small text nearby... but I guess I rather see clearly far than near. More useful that way, when driving or shooting at incoming enemies. Who cares if I can't read the fine-print then?