An open letter from two big Apple investors has urged the company to research the negative effects technology can have on children, and implement more robust parental controls to help avoid overuse of iPhones and iPads.

The letter comes from JANA Partners LLC and the Californian State Teachers’ Retirement System, who between them own more than $2 billion in AAPL shares. This puts them in a unique position to appeal to Apple and be taken seriously.

Apple already includes many parental controls in iOS, but most of them are pretty simplistic: disabling certain apps, or slapping age restrictions on certain iTunes content. The letter hopes for more granular controls that could allow parents to limit usage time or allow apps only between certain hours, for example.

It’s also looking for Apple to assign a key executive to the task of researching the effects of overuse on kids and reporting back to shareholders on an annual basis. Smart device overuse has been variously linked to sleep deprivation, depression, and even a lack of empathy in children and teenagers. However, these reports vary and a fuller investigation could help shape future iOS features.

The letter, entitled Think Differently About Kids, points out that Apple’s huge success and ubiquity means it is in a position to actually make a difference here. You can read the report in full right here for more details on the appeal and its various suggestions.

Whether or not Apple responds remains to be seen, but hopefully executives will at least take on board the fact that there is a clear demand for this kind of thing. In the meantime, though, there are other things you can do if you have kids who use iPhones and iPads. We recently penned a feature looking at exactly that: check out iOS tips for parents for some advice you can use right away.