Complex sentence: Actors may be deemed too old or too young for leading roles; being "too old" is more of a problem for women, who may find that their range of acting jobs drops precipitously after the age of forty (see ageism).
Split into simpler sentences: Actors may be deemed too old or too young for leading roles. Being "too old" is more of a problem for women, who may find that their range of acting jobs drops precipitously after the age of forty (see ageism).