Marussia test driver Maria de Villota has lost her right eye and remains in critical but stable condition following her crash on Tuesday.
Marussia said a surgical team at Addenbrooke's Hospital in Cambridge "embarked on a lengthy procedure to address the serious head and facial injuries sustained" in the accident.
The team said the operation began yesterday afternoon and she was in theatre until this morning.
Team boss John Booth said de Villota has lost her right eye as a consequence of the accident.
"We are grateful for the medical attention that Maria has been receiving and her family would like to thank the Neurological and Plastics surgical teams," said Booth in a statement.
"However it is with great sadness that I must report that, due to the injuries she sustained, Maria has lost her right eye.
"Maria's care and the well-being of her family remain our priority at this time. Her family are at the hospital and we are doing everything possible to support them.
"We ask for everyone's patience and understanding with regard to updates on Maria's condition. We will provide further information when it is appropriate to do so and with consideration for her family.
"In the meantime, we would all like to take this opportunity to praise the emergency services at Duxford Airfield, who were on stand-by yesterday, as is usual procedure for a Formula One test.
"With regard to the accident, we have embarked on a very comprehensive analysis of what happened and this work continues for the moment.
"Finally, we have been overwhelmed by messages of support for Maria, her family and the Team and we would like to express our sincere gratitude for those."