You see 8 week old Ben with his mother Claire for his 8 week baby check at the GP surgery. Claire had an uncomplicated pregnancy and Ben was born at term by normal vaginal delivery. Ben is doing well and is bottle-fed gaining weight along the 50th centile.
On examination, despite the rest of his examination being unremarkable you observe an absent red reflex in Ben’s left eye. The pupil appears grey in colour. His mother comments that his eyes have always appeared this way.
What is the most likely diagnosis?