Last Night's TV - Perfume, BBC4; Imagine, BBC1

Chandler Burr spends his life standing in his New York apartment, darting between the front door and his living room. The postman comes several times a day; packages are dropped off, the contents inspected and then sprayed, regularly and methodically, over different parts of Burr's anatomy. "Ooh!" he'll squeal occasionally. "Interesting." Or: "No! Juicy Fruit! Pot!"

Burr, we learned in last night's Perfume, is The New York Times's scent critic, a king-making role in a city where 1,200 new perfumes are launched each year (compared with 150 annually just a decade-and-a-half ago). Nearby, the fragrance hall of Macy's department store offers the most important industry trading ground in the Western world. It looks, to any rational person, like hell: gazillions of garishly lipsticked ladies bearing spritzers, all throwing themselves in the paths of passing customers. Still, the passing customers keep coming, and the industry keeps booming.

Burr thinks there are too many perfumes on the market now. It's an addiction, he said, a constant, unedifying quest for the new. Probably, Jean-Paul Guerlain would agree. He's the last in the great perfume-making family. A looming figurehead, he oversees the operations of heir apparent Thierry Wasser, clinging tightly to the traditions that distance his own perfume house from the big, bold operations flogging their wares at Macy's. Instead of marketing campaigns, he invites selections of "lady journalists" to his chateau for lunch, flying them in by helicopter, offering them champagne and fine food in the garden. Launching a new product is a rarity. When Wasser began work on a younger, fresher spin-off of Guerlain's Shalimar, it was seen as a definite risk.

A world away from Jean-Paul's picturesque model are the New York offices of Estée Lauder. When the company was tasked with creating a new mid-market perfume for Tommy Hilfiger, operations assumed gargantuan proportions. Various talking heads waffled on about "liquid rock'n'roll," and so the idea was born for Loud (currently available for £18.99 in Superdrug). Everything about it is at odds with Guerlain's refined offerings, from the music-themed bottle to the 3D effect of the logo. It looked, to my eye, utterly horrendous. But then what do I know? Last time I was their target market, it was Tommy Girl they were flogging. And anyway, Hilfiger liked it, as did the PR team in London, who set about pushing the thing with almost evangelical enthusiasm.

It was a neat little depiction of the old world versus the new. The linen-napkinned squeamishness of Europe versus the big, bold ambition of the US. It would be easy to romanticise the former, to sneer at the latter, were it not for a brief, but telling, bit of live television. On air to do that thing he so loathed, promote a new product, Jean-Paul made a passing racist comment about the work involved. Just like that, the rather less pleasant side of tradition was exposed; a PR bull in a perfume shop. No doubt Loud, on the other hand, with its endorsement from both Daisy Lowe and the Ting Tings will be a storming success. At least for a little while. Whether or not it'll be in the bargain bin later remains to be seen.

Last night's return of Imagine was utterly fascinating. Alan Yentob was talking to Oliver Sacks, who opened up for the first time about his "face blindness". He's had it since childhood, and it leaves him wholly unable to recognise even the most familiar of faces. To test him, Yentob held up pictures of famous figures to see who he'd get. Those he could name were all educated guesses: the Queen, because she looked "imperious and old", Barack Obama, giving a speech. It doesn't always work: Oprah, "young black and famous" is inferred to be Michelle Obama. A stab at Elvis is equally unsuccessful.

Thanks to Sacks's own neurological expertise, he can talk about his condition with remarkable authority. Amazingly, he can't even recognise himself, so mirrors and windows can be confusing. One incident saw him patting down his hair when faced with a similarly bearded man on the other side of the window. But his wasn't the only experience we heard about. Working on his book The Mind's Eye, Sacks had come across all sorts of cases – people who have come to him, he says, as a kind of "last resort". There was artist Chuck Close, also face-blind, who has made a career out of painting ultra-real, giant portraits. Not being able to recall images has left him looking at people not as fixed subjects but as "a continuum" – every time they move, they're a new sight. And there was Danny, a deaf former restaurateur, whose vision is slowly diminishing until, one day, he will become completely blind. And Sue, who lacked three-dimensional vision her entire life until a few simple visual exercises saw her slowly regain it. My favourite story, though, was that of Howard Engel, author of the Benny Cooperman crime novels. Awaking one day to find himself faced with a newspaper written in a foreign alphabet, he assumed he was the subject of a practical joke. Until, that is, he looked around and realised he couldn't read a thing. A stroke has left him able to write, but not to read, at least not conventionally. Since the incident, he's managed to devise a whole new kind of reading, imperceptibly tracing the shapes of the letters with his tongue on his teeth so he can understand them. His latest work, Memory Book, has been his most successful ever.