Post-concussion syndrome
About 10% of people with PCS develop sensitivity to light or noise, about 5% experience a decreased sense of taste or smell, and about 14% report blurred vision. People may also have double vision or ringing in the ears, also called tinnitus. PCS may cause insomnia, fatigue, or other problems with sleep.
Harry Carson
Harry Carson authored his second book "Captain for Life" published by St. Martin's Press in 2011. In his book he documents his experiences with Post Concussion Syndrome. He was one of the first former professional athletes to share his own personal first hand experiences years before the long term effects of concussions and chronic traumatic encephalopathy (CTE), long before the subject became a "hot button" topic.