 Several days before he started writing the episode , he received a call from Bernard Cribbins , who proposed a scene in which his character , Wilfred Mott , would fire a paintball pellet at a Dalek 's eyestalk . He proposed it as a reference to the Peter Cushing Dr. Who films that he starred in in the mid @-@ 1960s , and thought it would provide comic relief in between heavy exposition . The Dalek 's response — evaporating the paintball and replying " My vision is not impaired ! " — was added after Cook reminded Davies it was " obligatory " to invert the recurring phrase spoken when a Dalek was blinded ( " Vision impaired ! " ) , and remove a weakness the Daleks had exhibited since their first appearance in the 1963 – 1964 serial The Daleks . Wilfred 's reaction to Rose after she blew up the same Dalek — asking her if she wanted to swap weapons — was likewise added by Cribbins by way of an ad @-@ lib during filming . 
