Former Denver Broncos defensive lineman Dave Studdard has joined a long list of former players who are suing the NFL over lingering health issues.

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Studdard believes that the league withheld information about the effects of head injuries.

Studdard estimates he took more than 40 hits to the head which he refers to as "dings."

"Taking a ding is like when you go head to head right here with another player to just where it kind of knocked you back and just kind of takes all your peripheral vision out of the way so you get tunnel vision. So I can only see this way," said Studdard.

Studdard says his short-term memory has been damaged -- he sometimes forgets where he is and where he came from.

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