Dixon aims to improve vision

The Kiwi has had an implant, called Intacs, placed in the corner of his left eye. The implant consists of two crescents that form a ring around the edge of the cornea. The idea behind them is use their weight to flatten the cornea without permanently destroying tissue.

"My eyesight has never been perfect," said Dixon. "On some of these ovals, and especially Indy, it needs to be. The problem was I had to squint to get 20-20. I can still get 20-25 or 20-30 out of them, but it's obviously not as good as it can be and that's what I'm aiming for.

"The stuff that I'm getting done now can take up to three months to be optimal," he explained. "None of us has that amount of time. The doctors found it quite hard because I don't see the effects straight away and I've wanted to change things so often. They're obviously trying to pull back on it and I'm trying to push forward so we'll see what comes out of it."

The Toyota engine test gave Dixon a chance to evaluate the latest road course package on his Ganassi Racing G-Force.

"(The car) has evolved since I drove it last," he said, having been a part of the initial road course trial at Miami-Homestead three months ago. "It's getting better. There are a few things that they need to clamp down on. But there were no real issues and everybody got a lot of laps in."