Anyone over the age of 14 can ride an e-bike without needing a licence, but by law the motor must have a maximum power output of 250W.
This restriction limits the e-bike’s speed to 15.5mph (25km/h) and it must also have pedals to be classed as a bicycle rather than a motorcycle.
Ms Firth was diagnosed as partially sighted at the age of five but her vision has deteriorated in recent years.
She has corneal decompensation, which she describes as “extreme double vision”, and nystagmus, an involuntary shaking of the eye.
On her commute to work, Ms Firth said she walks down the Moor in the city centre, and often feels “scared” when passed by fast e-bike users.
She told the BBC: “They whip in and out between crowds which is fine when you can see people coming, but I can’t see anything at all on my right side and only when they are very close on my left. I can’t move out of the way of the danger fast enough.”
Ms Firth said another hazard faced by the visually impaired was “pavement clutter”, when delivery drivers leave their bikes in the centre of the pavement while dropping off food.
She said: “I have managed to get my cane stuck in between the wheels of the bike. Other friends of mine have even fallen over parked bikes.”
