When he removed the tape, however, he discovered his entire body was covered in bruises from bumping into things. ''It was as if I had been beaten up,'' Aslam says. ''If I had been able to see, I would have noticed the bruises. But as I couldn't, they accumulated. I was stunned.''

Aslam, who now lives in London but had emigrated with his family from Pakistan to northern England when he was 14, had spoken to blind people about their condition but it wasn't until he ''blinded'' himself, which he did for one week three times during the four years it took to write the novel, that he felt he had the ''visceral'' knowledge he needed.

''I went for walks in the hills around my home and the information came to me. Plimsoll shoes, for instance, help you feel the ground better. I could eventually tell the difference between concrete, grass, mud or plastic. And I drove nails in front of the cooker so I knew where to rest my feet when I cooked. It was so my toes wouldn't catch fire.''

Taking such measures to understand a character might seem extreme but Aslam has a reputation for being dedicated to his craft.

He writes his first drafts in longhand, working up to 17 hours a day, usually at night, and pays attention to detail, editing his work with a ruthlessness that, on one occasion, reduced 100 pages of a manuscript to a few sentences.

He lives alone and drapes his windows with black cloth while writing, refusing to see people for weeks at a time. His family even delivers his food while he is sleeping.

''In my personal life, I am quite hesitant when I approach other people,'' he says. ''Because of this habit of writing over the past 20 years, I am used to being on my own. It makes it difficult for me to connect to people unless I am very sure of that [relationship].''

The blind character in his new novel is a Pakistani widower called Rohan, whose son, Jeo, and adopted son, Mikal, travel to Afghanistan a month after September 11, 2001. The invading Americans are pursuing al-Qaeda and the two foster brothers, who are in love with the same woman (Jeo's wife), want to help care for wounded civilians. But they are ''enlisted'' by Taliban fighters and end up in a skirmish with American soldiers that has devastating repercussions for the brothers and their family.

The Blind Man's Garden, for which Aslam interviewed more than 100 Afghan refugees in Britain, is his fourth novel, his second about Afghanistan. His previous novel, The Wasted Vigil, which he discussed at the Perth Writers Festival in 2009, is about a group of people in Afghanistan with opposing ideological viewpoints, including a CIA agent and a jihadist. He visited Afghanistan to research it.

His first novel, Season of the Rainbirds, set in rural Pakistan, came out in 1993 when Aslam, now 46, was only 27. It won Britain's Betty Trask Award and was shortlisted for the John Llewellyn Rhys Prize and the Whitbread (now Costa) first novel award.

His second novel, Maps for Lost Lovers, which explores the tensions within a Pakistani community in northern England after an honour killing, won the 2005 Kiriyama Pacific Rim book prize, was longlisted for the Booker prize and shortlisted for the International IMPAC Dublin Literary Award.

Aslam, who studied biology at university before turning to writing, is one of several Pakistan-born authors - including Mohsin Hamid, Mohammed Hanif, Kamila Shamsie and Daniyal Mueenuddin - who have made their mark in English fiction in recent years.

Their work draws from Pakistan's tumultuous political and social landscape and, in Aslam's case, the consequences of September 11, 2001. He describes the period between then and the Arab Spring as a clash between ''an incomplete understanding of the East and an incomplete understanding of the West''.

In The Blind Man's Garden, September 11 is used as a hinge ''to see how much of the inadequacies of the pre-September 11 system made things worse during the past decade''.

This includes the place of women and minorities in society, the relationship between East and West, and the inequalities of wealth and opportunity, but also the West's arming of the Mujahideen after the Soviets invaded Afghanistan.

As in The Wasted Vigil, all sides in The Blind Man's Garden are flawed. One of the brothers is tortured by the CIA in a ''black site'', a holding cell before prisoners are sent to Guantanamo Bay, while Rohan's family suffers at the hands of suicide bombers who kill schoolchildren ''stained'' by Western education.

Aslam's father, a poet and filmmaker from a bohemian family who wrote in Pakistan under the pen name Wamaq Saleem, advised Aslam to ''always write about love''. This is evident in The Blind Man's Garden, which has a strong political message - promoting moderate Islam against militant Islam - but also invokes the power of love and beauty by juxtaposing them with brutality and inhumanity.

Aslam's family came from a village outside Lahore called Gujranwala, where he was exposed to both moderate and fundamentalist Islam.

When his parents were engaged, the marriage was almost called off when one of his father's relatives mentioned the word ''wine'', considered idolatrous by strict Muslims.

''My mother, a devout Muslim, will love you, feed you and lend you the money,'' Aslam says. ''If you come to her house, she will sleep on the floor and give you the bed, everything. She is a decent human being. But she is unshakeable in her belief as a Muslim that as a non-Muslim, you are doing something wrong.''

To experience a rigid society is a huge gift for a writer, Aslam says. ''As a writer, I know there isn't one way of being an aunt or an uncle, or of being a Muslim. I know Muslims who drink alcohol, but I also know Muslims who would not have a picture on the wall.

''People ask, 'How did things change for you after September 11?', and I always have a feeling that I became a Muslim on September 11, in that if someone asked me before whether I was Muslim, I would have shrugged and said, 'Well, you know, I drink alcohol, I don't say my prayers, I have never fasted and don't intend to, sex before marriage isn't a problem for me, and I don't believe in God'.''

That is directed not only at Westerners who think all Muslims have beards and don't drink alcohol, he says, but also at al-Qaeda, because it's his way of refusing to accept the fundamentalist definition of Islam.

Aslam's father and uncle were both communists who were detained several times by General Zia-ul-Haq's regime. After his uncle was tortured with electricity, his father fled to Britain in 1982 with the family, which included Aslam's two brothers and a sister.

They settled in Huddersfield in West Yorkshire, where his father became a garbage collector. Maps for Lost Lovers draws on this experience, including the racism they confronted in England.

Aslam could not speak a word of English when he arrived in Britain. He learnt the language by writing out entire books, including Melville's Moby-Dick, Nabokov's Lolita and Faulkner's As I Lay Dying, and has reached a point now where he is fiercely devoted to little else but writing.

''You enter a state of grace when you sit down to write,'' he says. ''I really don't understand what happens afterwards. I never wanted to be a writer but I always wanted to write.''

His next project, after he finishes a short novel he is working on, is a trilogy set in Pakistan and the West from the 1980s to the present. It will be about Wamaq Saleem, the fictional poet based on his father who appears in all his novels. Aslam says he is living his father's dream to be a poet. ''I always felt, growing up, there was a kind of wound in my father, as if his real life didn't happen.''

But dedication to writing carries a penalty, too. When asked if he ever wants to have his own family, Aslam pauses a moment before answering in a softer voice.

''I am now this age when I am beginning to realise that my writing has more or less cost me everything,'' he says. ''In my youth, it has cost me most friendships. It has certainly cost me almost all love. It is difficult.''

■ The Blind Man's Garden is published by Faber & Faber at $29.99.