VIEWERS are in the rare position of being spoiled for choice by the terrestrial channels tonight. Akiro Kurosawa's astonishing epic, Ran is on World, while Pearl is showing two award-winning documentaries, one about the development of a human life and theother about infertility. JAPANESE director Kurosawa based his huge tormented vision Ran (World, 9.30pm, Original Running Time, 160 mins), partly on a Japanese myth and partly on King Lear, and the 1985 film is widely considered the best screen translation of Shakespeare. Kurosawa described the film as ''human deeds seen from heaven'', and the tale of human drama and tragedy is indeed viewed with a sense of distance. Tatsuya Nakadai portrays a great but ageing warlord who divides his kingdom between his three sons and, true to the story, dispossesses the one who's most loyal to him. ''Ran'' (chaos) ensues as the eldest sons battle for power encouraged by the evil Lady Kaede, powerfully portrayed by Mieko Harada. The battle scenes are some of the most terrible ever filmed, and the outcome bleaker than Shakespeare's. Admittedly, the film's power is diminished somewhat on the small screen, but it's still a grandiose vision. DESPITE the soppy umbrella title, The Greatest Love of All, both documentaries involved promise to be fascinating and educational. The first, The World of the Unborn (9.50pm) uses advanced photographic techniques to film the making of a baby - and, oddly, there's not a stork in sight - from the formation of egg and sperm, through conception and growth in the womb, to the birth. The Agony and the Ecstacy looks at the widespread problem of infertility. About one in eight couples in Britain and the US need some sort of medical help to have a child. This documentary looks at the problem and the techniques available to overcome it. AFTER all that worthy viewing, try something in a far lighter vein in Bernard and the Genie (Pearl, 12.20am, ORT 70 mins), a BBC-made Christmas comedy starring Lenny Henry (True Identity) and Rowan Atkinson (Blackadder, Mr Bean). Cheerfully proclaiming ''sit ye, sit ye'', slimy boss Atkinson sacks the hapless Bernard (Alan Cumming) a few days before Christmas. His girlfriend then leaves him and his flat is cleaned out. It would seem things couldn't get worse but then Bernard accidentally summons a lamp genie (Henry) whose peculiar ways of granting wishes have disastrous results. Great fun. GASTRONAUTS should sample A Cook's Tour of France (BBC, 9.25pm), the first of a six-part series in which writer Mireille Johnston travels around the country seeking out the best in French cuisine. Tonight she's on the Atlantic Coast learning about oysters.