Behind the scenes with Guide Dogs UK
Living in London, dodging bikes, traffic and A-boards, not to mention crossing roads, can be stressful enough using all five senses.
So for someone who loses their sight, which happens to a person every hour in the UK, navigating the capital can be even more hazardous.
Guide Dogs UK is determined to give blind and partially sighted people more freedom to move about, training hundreds of animals a year at its training school, an Oxbridge for dogs.
Only the elite make it through, with the ones who are better skilled in other areas - like those who like to scavenge - finding work as an emotional support dog, bomb sniffing dog or the police.
Trainee guide dog Digger, who is 21 months old, is only three weeks away from being homed with his new owner - a fast-walking office worker who travels a lot on London transport. These are all things that Digger is perfect for.
We meet lead guide dog mobility instructor Becca Gamble, who has been working for the charity for nine years, to find out how Digger is doing and how she trains the dogs.
The offices in Euston would be a dream for any dog lover with each desk fenced in a pen holding a dog and an office worker.
We head out into Euston with Digger and, despite plenty of obstacles and tempting scraps to distract the pure Labrador, he is clearly well on his way to graduating, only making a few errors as we walk around.
Becca said: "At the end of training we will work with the routes that the guide dog owner wants to take and ensure the dog knows them well enough.
"If their circumstances change we can go back and walk the dog along a new route for them. Some dogs can pick up a new route the first time they do it.
"The most difficult thing for a dog to learn is often leaving enough room on its right-hand side as humans come in all shapes and sizes.
"Digger has gone through fairly steadily though. He's just a really nice dog. The volunteers he lives with absolutely love him."
It's a tough life for a London dog. Digger will retire in about eight years of living in the capital, but in outer boroughs dogs retire after around 10 years.