The short answer is everything and nothing.
There is no exact age when one needs to purchase elder friendly products, but statistically speaking, there is a strong correlation with age. Some of us have eyesight that starts to fade around the age of forty-five. Others keep their perfect 20/20 well into their eighties. The older one gets, especially after one reaches the age of sixty-five, the more likely he/she is inclined to purchase a product with one or more elder friendly features.
Instead of automatically filling your household with elder friendly everything after a birthday, it is important to critically asses the relationship between perception, cognition, mobility and bio-mechanics and the features on a product they interact with. If your arthritis acts up every time you try to use a standard computer keyboard, and then by all means, buy an ergonomically designed keyboard.
Just remember understand the features you are need (and those you don



