@burcinc-- That probably depends on the exact toy/tool but there are studies which show that certain exercises and educational toys can help children learn faster and better. A healthy child will develop perception just fine in a regular environment as long as there are enough sensory stimuli. What these toys basically do is provide more stimuli for the child. I don't see any harm in these and I do think that they may be very beneficial.
Children are like sponges, ready to learn and I think that they have a far greater capacity than we realize. Children of parents who don't spend much time with their children, play with them and speak with them, don't do as well in school as other children.