The seven ages of man that Jaques describes are the stages of life: from birth and childhood to adulthood, old age, and finally extreme old age. When a person is "sans teeth, sans eyes, sans taste, sans everything," they are close to death.

Sans means "without," so the statement means that at the end of life one is without teeth, without eyesight, and without the ability to taste. Jaques sums this up as without everything.

Jaques is being comically imprecise in this statement. He mixes the literal (old people being without teeth) with the figurative (old people being without eyes.) Their eyes have not literally fallen out like their teeth: he means that they are blind or see with difficulty. Also, while the elderly do become less taste sensitive, it would be more common to note their deafness. Finally, Jaques just gives up and uses the vague word "everything." He is describing how helpless the very old became in a time before medical interventions could help them to a better quality of life.

Shakespeare pokes fun at the lack of finesse Jaques has with words, but Jaques's words show that the Forest of Arden is no magical place. The same process of aging and death that happens throughout the world happens here as well.