Certain questions about eye examinations in England

Investigator Adrian Smith alerts us to this pair of studies which, he says, “leaves some scope for further studies, not in England, however”:

“Why don’t older adults in England go to have their eyes examined?“ Darren Shickle and Marcus Griffin, Ophthalmic and Physiological Optics, 2014 Jan;34(1):38-45.

“Why don’t younger adults in England go to have their eyes examined?“ Darren Shickle, Marcus Griffin, Rebecca Evans, Benjamas Brown, Almira Haseeb, Sharon Knight, Emily Dorrington, Ophthalmic and Physiological Optics, 2014 Jan;34(1):30-7.

BONUS QUESTION: Of the group, why did only Darren Shickle and Marcus Griffin write a study older adults in England?