How are dogs the same / different?
Look at dogs, talk about similarities and differences within species- pattern, colour etc. They look so different, and yet are all dogs.
Now look at your eyes in a mirror - What colour are they? Look at other members of your family - are they all the same. See if a grown up can call other members of your family and friends - what colour are theirs?
Make a tally of how many people have blue, brown, green or hazel, then put them on a pictogram, or bar chart. What colour is the most common?