Lens began his career at AZ, and after a loan at NEC, played a part in their 2008–09 Eredivisie triumph.

When head coach Louis van Gaal left the team for Bayern Munich, Lens saw a chance for himself to play more matches.

On 6 October, Lens scored his first two goals in the Ukrainian Premier League in a crushing 9–1 victory over Metalurh Donetsk.

On 23 April 2015, Lens was sent off for two bookings in the first half, as Dynamo lost 0–2 at Fiorentina and were eliminated from the quarter-finals of the Europa League.

[5] In his second and final season for Dynamo, he managed to help his team win both the Premier League and Ukrainian Cup without suffering a single defeat in both competitions.

[6] Lens scored his first English Premier League goal on 29 August 2015, securing a 2–2 draw at Aston Villa.

Lens stated he was unhappy at Sunderland, suggesting he could leave the club in the January transfer window as he "did not come to the Premier League to sit on the bench".

[14] He made his debut for the club on 26 August 2022, replacing Jordan Leborgne in the 69th minute of a 2–0 home win over Bourg-en-Bresse Péronnas.

In 2009, Lens was called up for Suriname's squad by national team coach Wensley Bundel, for the Parbo Bier Cup.

On 3 May 2010, Lens was called up for the Dutch national team, as a part of the preparations for the 2010 FIFA World Cup.

[20] However, on 27 May 2010, Netherlands manager Bert van Marwijk announced that the player would not be part of the final 23-man squad participating in the competition.

[22] Lens became a regular member of the Dutch team under the management of his former AZ coach Louis van Gaal.