Riders hear this constantly. It is worth understanding why it usually helps the rider's case rather than the driver's. Every driver owes a duty to look properly before emerging or turning, and that duty includes looking for road users who are smaller and easier to miss than a car.
If a rider was there to be seen, in reasonable conditions, with lights on and no obstruction, then a driver who failed to see them has fallen below the standard expected. That is carelessness, not an excuse.
The position is different where something genuinely prevented the driver from seeing the rider, such as a bend, a concealed entrance, dazzling sun or a vehicle obstructing the view. Where that happens, the question becomes what each party could reasonably have done, and responsibility may be shared. A solicitor can tell you which situation you are likely to be in once the evidence is in.