SOUTH BEND, Ind. (AP) — Even somebody with vision as compromised as left tackle Liam Eichenberg wound up having against Florida State can see No. 4 Notre Dame is riding one of the nation's top offensive lines.

“I really feel like we have the best o-line in the country,” Fighting Irish quarterback Ian Book said following the 42-26 victory over the Seminoles. “I’ve been with all these guys for a long time, and they just lay it all on the line to protect me, to protect the running backs, and they’re just fun to be out there with.”

Eichenberg, left guard Aaron Banks, center Jarrett Patterson, right guard Tommy Kraemer and right tackle Robert Hainsey have coach Brian Kelly practically gushing with praise.

“(In 30 years), there’s not a group that I’ve coached that those five guys work so well together,” Kelly said.

Pro Football Focus has ranked the line No. 1 nationally: Notre Dame graded at 96.9, ahead of Georgia and Clemson. Louisville (1-3, 0-3 ACC), which visits Notre Dame (3-0, 2-0) on Saturday — is tied for fourth.

The Irish aren’t satisfied, though.

“Obviously, we need to improve on a lot of things,” Eichenberg said Tuesday, “but I think pass protection’s been solid. I think our run game’s getting a lot better. It’s just a lot of the technique needs to be cleaned up, and a lot of fundamentals and assignments, so I mean there’s always room to improve, but I think we’re going in the right direction.”

Eichenberg’s direction temporarily came to a screeching halt when he was poked in the left eye — accidentally, he says — during the second quarter of the win over Florida State. His eye soon swelled virtually shut, and he was still sporting a deep shade of purple Tuesday.

The fifth-year senior returned to the game in the third quarter with the addition of a protective visor.

“I could see for the majority of the time,” said Eichenberg, who added that it took a “full quarter” to get his contact back in.

Others were impressed by Eichenberg’s desire to keep playing.

“I think all our guys had a lot of respect for him, but it just solidified the kind of respect they had for him as a leader on our football team,” Kelly said. “When you see cornerbacks and guys he doesn’t see a lot and DBs go up and talk to him, you can tell that had an effect on other players in our program about him being gritty and fighting through it to get back on the football field.”

The amount of time the Irish offensive line has spent on the field borders on ridiculous.

Eichenberg made his 29th straight start last week. Kraemer owns 32 career starts over the last four years, Hainsey 24 over the last three, Banks 22 over the last three and Patterson — the lone junior among seniors — 16 over the last two. That’s 123 combined starts.

While none of the five players is rated near the top among pro prospects, Hainsey (No. 23), Banks (24), Eichenberg (28) and Patterson (30) were all in the top 30, per PFF, over the offseason.

Together, the five have helped Notre Dame average 270.7 rushing yards, fifth in the nation, including 353 against the Seminoles. They have allowed just three sacks over three games.

“They don’t ever show any weakness,” redshirt freshman running back Kyren Williams said of the line after rushing for 185 yards and two touchdowns on 19 carries against Florida State.

An appreciative Williams has a specific goal for this week, and it has nothing to do with his own stats, at least directly.

“We’re trying,” Williams declared, “to get the offensive line the (game) ball.”