testing if settings field has been updated

I currently have an options page associated with my theme that registers settings and I have a few settings fields there. I am able to validate them and update the db… so all seems like it;s working from that end.

To use these in my theme, I call something like:

<?php $options = get_option('theme_options'); ?>
<?php echo $options['option_name']; ?>

but I would like to add an if statement to check and see if a particular field has been filled.

I tried the following, but it isn’t working.

<?php if ( get_option ( 'option_name' )) { //do something } ?>

I need to get to the field name somehow… I’ve been searching for a while and there are many tutorials on building a settings page – but not many on using the new options afterward. Any help would be appreciated.