for my $var (@vars) {
    print "Value: " . $hash_ref->{lc $var} . "\n" if exists $hash_ref->{lc $var};
}

##</code><code>##

for my $var (@vars) {
    my $new_var = lc $var;
    print "Value: " . $hash_ref->{$new_var} . "\n" if exists $hash_ref->{$new_var};
}

##</code><code>##

for my $var = lc $_ (@vars) {
    print "Value: " . $hash_ref->{$var} . "\n" if exists $hash_ref->{$var};
}