The Book of British Birds notes that in the case of the golden eagle, its eyes “are, in fact, as large as they could be without becoming so heavy as to impair flight. ”
Grāmatā Book of British Birds ir atzīmēts, ka klinšu ērgļa acis ” ir tik lielas, cik vien lielas tās var būt, lai to smagums neapgrūtinātu lidojumu ”.