The eyes are the best sense in penguins.
A membrane enables sharp vision underwater and in the air. Penguin eyes are adapted for underwater vision. Their eyes are their primary means of locating prey and avoiding predators. On land penguins are near sighted.
Penguins have exhibited colour vision, sensitive to blue, green and violet light.
Their hearing ability is good but their sense of smell is of little importance although the olfactory lobe of the penguin brain is large.
The sense of taste in birds is poorly developed and is assumed to be the same in penguins.