There are two important issues regarding women in Hamlet: how Hamlet sees women and women's social position. Hamlet's view of women is decidedly dark. In fact, the few times that Hamlet's pretend madness seems to veer into actual madness occur when he gets furious at women. Gertrude's marriage to Claudius has convinced Hamlet that women are untrustworthy, that their beauty is a cover for deceit and sexual desire. For Hamlet, women are living embodiments of appearance's corrupt effort to eclipse reality.
As for women's social position, its defining characteristic is powerlessness. Gertrude's quick marriage to Claudius, though immoral, is also her only way to maintain her status. Ophelia has even fewer options. While Hamlet waits to seek revenge for his father's death, Ophelia, as a woman, can't act—all she can do is wait for Laertes to return and take his revenge. Ophelia's predicament is symbolic of women's position in general in Hamlet: they are completely dependent on men.