Police carrying out road safety checks in Holyhead and Bangor arrested a man on suspicion of drug driving.

Around 320 vehicles were stopped by road patrol officers as part of a UK-wide campaign, coinciding with shorter days and longer nights over winter.

Operation Dark Night, led by the National Police Chiefs' Council (NPCC), focus on vulnerable road users such as pedestrians, cyclists and horse riders. Checks are also carried out on driver eyesight and adherence to speed limits.

Drivers were asked to read a number plate from a 20 metre distance - the primary legal vision standard in the UK. But seven drivers failed the eyesight tests - including some who had failed to read the number plate at 4, 8, 10.5 and 13 metres.

In those cases, they immediately lost their licences and were taken home by police. The DVLA will now be informed to all those who failed under Cassie's Law.

It was introduced in February 2013 following the death of 16 year-old Cassie McCord from Colchester, who was killed on her way to school by a pensioner who lost control of his car.

Just three days before, 87 year-old Colin Horsfall had failed an eyesight test and refused to surrender his licence. Despite being told not to drive, he struck and injured three girls - including Cassie, who died later in hospital.

Now, any driver who fails the roadside eyetest faces losing their licence straight as well as three penalty points and a fine of up to £1,000.

Sergeant Leigh McCann from the Roads Crime Unit at North Wales Police said: "We are pleased to be supporting this national campaign to help continue to ensure that our roads are as safe as possible for all drivers, pedestrians, cyclists, motorcyclists and other road users."

"As we approach the winter months, it is vital that we do all we can to make sure that when you get behind the wheel you are not putting yourself or others at risk of injury or worse."

"We announced last month that we would be supporting this national campaign and that we would be carrying out roadside checks across the region. Yet today, we’ve uncovered several offences including defective tyres, drug driving and driving without insurance."

"One of those stopped could not read the number plates at 4 metres, which is, quite frankly, unbelievable. These roadside tests will continue, including at any traffic-related stops in order to ensure everyone’s safety on the roads."

"Over time vision can decline gradually and so it is recommended by eye experts that all motorists have regular eyesight tests – every two years unless advised otherwise by an optometrist – to help ensure that vision remains roadworthy."

The roadside checks led to one man being arrested after he tested positive for cocaine, while five people were reported for driving otherwise than in accordance with a licence.

Officers also found vehicles with defective tyres and no tax or MOT and drivers failing to wear seatbelts or driving without insurance.

One driver was caught with front window tints allowing only 25% of light - an immediate offence - but they were removed on the spot to prevent their vehicle being seized.

Sgt McCann added: "We make no apologies in trying to reduce serious and fatal collisions in line with road safety initiatives such as this one held today."

"Further operations will be carried out over the next few weeks as we are committed to making the roads of North Wales as safe as possible. If this operation prevented one person from being injured or worse, killed – then we see it as a success."