$ perl -E'use strict; my $x = 10; eval q{ my $y = $x; }; say $y'
Global symbol "$y" requires explicit package name at -e line 1.
Execution of -e aborted due to compilation errors.

$ perl -E'use strict; my $x = 10; eval q{ my $y = $x; say $y };'
10

$ perl -E'use strict; my $x = 10; my $y; eval q{ $y = $x; }; say $y'
10

$ perl -E'use strict; my $x = 10; my $y = eval q{ $x }; say $y'
10