Bad eyesight and a borrowed cue will not stop Stephen Maguire fancying his chances when he goes head-to-head with Ronnie O'Sullivan in the quarter-finals of the World Snooker Championship on Tuesday.

The 41-year-old has already guaranteed £50,000 by reaching the last eight and plans to spend a slice of his winnings on improving his vision and reimbursing the friend whose cue he borrowed after a below-par first-round win over Shaun Murphy.

Maguire, who revealed he had swapped cues after brushing aside Zhao Xintong in the last 16, said: "I need to get my eyes tested after the tournament - at the moment I feel like I'm playing from memory.

"I had laser eye surgery when I was 30 and the girl told me it would last 10 years, so hopefully I will be able to see a wee bit of difference if it's possible to get it changed."

Maguire is a two-time Crucible semi-finalist but has not reached the one-table set-up since 2012, when he was surprisingly beaten by 13th seed Ali Carter, a result the Scot considers to be one of his greatest regrets.

Ronnie O'Sullivan

"I'd love to play in the one-table set-up again," added Maguire. "I didn't do myself justice the last time. It annoys me to this day that I went in and I don't know who I thought I was to give Ali Carter no respect, and I paid for it."

Maguire has lost all three of his previous Crucible clashes against O'Sullivan, who swept into the last eight with a 13-4 win over Mark Allen.

And he admitted their first-round clash in 2005, which he led throughout before losing in a final-frame decider, was another of those classic Crucible matches that gave him plenty of cause to wonder what might have been.

"The one that stands out is that first-round match the second time I was here," admitted Maguire.

"I should have won that match. I was strangling him and in the end I just said, 'on you go'. That still haunts me. Who knows what would have happened if I had managed to win that match?

"I have never beaten Ronnie here but I fancy beating anybody. I know how good I can play and how bad I can play. On the good days I'm good, and on the bad days I'm atrocious.

"We'll see which version turns up on Tuesday."