Loris Karius has blamed the floodlight system used in Turkish stadiums for causing his vision a problem according to Fotospor.
Per the source, Karius has blamed the floodlight system for blinding him at times this season and disrupting his concentration.
Fotospor wonder whether this could be tied to the concussion Karius suffered in the Champions League final between Liverpool and Real Madrid.
Real Madrid defender Sergio Ramos collided with Karius moments before his first mistake in the 3-1 defeat.
The report claims that the doctors who conducted tests on Karius after the game declared that the concussion could affect his sight.
However, Karius had tests in Boston in the United States following the final.
One of the medics, Dr Ross Zafonte did admit it was “possible” the injury “would affect performance”.
But he did also say that the keeper was expected to make a full recovery following the examination.
“We expect him to make a full recovery based on the results of the examination,” Dr Zafonte was quoted as saying by the BBC.
Karius has come under criticism from sections of the Turkish media and Besiktas fans this season.
He has, however, managed to keep his place as first-choice keeper for the Istanbul giants throughout his time at the club.
Karius has conceded 45 goals in 30 appearances for Besiktas in all competitions this season.
The Black-Whites have conceded the highest number of goals in the Super Lig top-five (31).
The 25-year-old keeper is into his second season on loan at Besiktas from Liverpool.
Karius is expected to return to Liverpool following the end of the current campaign.