Jr. missed the last half of the season due to concussion from a wreck back in June. It was pretty bad, his vision was messed up and he was having issues with nausea.
NASCAR changed rule and will now allow drivers returning from injury some test time - so long as no data logging devices are on the car (so teams don't use this as a test session for set ups, etc, only to evaluate driver health/ability in car).
Personally, given he has sat out for concussions in the past, plus how bad this one appeared to be for him, I think I'd retire rather than risk becoming a vegetable (or dead).
Below from
www.jayski.com. Looks like the original was from ESPN.
Earnhardt Jr. confident ahead of upcoming private test: "I feel 100 percent," Dale Earnhardt Jr. said Friday after accepting the NMPA Most Popular Driver award during the 2016 NASCAR Sprint Cup Awards at the Wynn Las Vegas. "I don't feel we're going to have any issues." Earnhardt, 42, missed the final 18 races of the 2016 Sprint Cup season because of a concussion in June that impacted his vision and balance. He plans to return for the 2017 Daytona 500 as long as NASCAR-approved on-track tests don't trigger any symptoms. Earnhardt will do a private half-day test this month in which he won't be able to have data-acquisition sensors on the car in order to limit any advantage the organization gets from the private test. The test had not been allowed until NASCAR made a rule earlier this year that permits a private test following injury. "I had balance and vision issues and some nausea when I was going through the illness, so we'll just make sure that I don't have any vision issues and no nausea," Earnhardt said. "I don't expect anything, because I've been through the simulator several times. I was getting sick in the simulator before I was injured. I have been able to do the simulator without any nausea or any vision issues at all." If things go well, Earnhardt will do the NASCAR open test Jan. 31-Feb. 1 at Phoenix International Raceway. Earnhardt said he probably will have a doctor at the first test but that he shouldn't need a follow-up examination if he feels fine during the test.(ESPN)(12-3-2016)