Cactus is the dramatic story of Colo (Isabelle Huppert), a visiting French woman, holidaying in Australia and Robert (Robert Menzies), a blind lecturer at a training school for the blind.
The film opens with a car accident. Colo regains consciousness in hospital, and discovers she has been left sight-less in one eye. As the film unfolds, Colo's subjective viewpoint grows progressively more blurred, whilst in the drama, her doctor and Australian friends conceal from her the possibility that total blindness may be only a matter of time. Colo has no resources to cope with the impending tragedy, and when she begins to suspect blindness, her withdrawal from the world and her friends becomes complete.
Her host, Tom (Norman Kaye), a cacti fanatic, persuades Colo to join him in attending a gathering at which cacti lovers meet and exchange secrets. One of the members, Robert, who has been blind since birth, despite his handicap, has managed to grow one of the finest collections of cacti in the country. Colo is stunned by his ability to feel things grow, and is touched by his serenity and peace of mind.
Robert has never made love to a woman, or enjoyed the physical pleasures that Colo has experienced. His wit and knowledge surprises and entertains Colo, yet, at the same time, intensifies her sense of isolation and worthlessness. Despite Robert’s reluctant attempt to cheer her up, Colo reaches the bottom of the pit. It is at this point that the mood of the film changes.
Colo is becoming aware of other dimensions in her life, but selfishly, she does not realize that her physical closeness is starting to affect Robert. Inevitably they are drawn closer and closer, and their eventual love-making is an act of extraordinary tenderness and sensuality.
Robert now is thrown into total confusion and chaos. The urgency of his physical awareness replaces the security of his inner-self and when Colo's husband arrives in Australia, Robert is not equipped to cope with his jealousy and anxiety. Colo however, is forced to make a decision about the security of her “old world" and the uncertainties, risks and challenges of her “new world" in which she is confronted with the love and affection, the depth and humour of a man, who, in the eyes of the world, has nothing to offer. She has to make an important decision.
Throughout the film the symbol of the cactus is a recurrent motif. The cactus is a plant that thrives on neglect, and it provides the drama with a brittle but telling edge. Both characters have a totally different concept of what they “see". For Robert it is a blend of imagination and legend. For Colo, it is a fusion of memory and impulse - two blind people teaching one another how to see.
The moral is clear. Domination by our surface desires cannot bring us happiness. The neglect of our inner self prevents us from discovering the real nature of our consciousness.