The tissue in the eye's cornea may opacify and the patient may go blind.    From Wordnet, Princeton University. 

The westering sun slanted in through the window and he didn't bother to push the contact that would opacify the glass.    From Wordnik.com.  [Destination Brain]

While cause for laughter, these manipulations, like Google's systematic search-and-destroy efforts, serve to deaden, opacify, obscure, and delete information.    From Wordnik.com.  ["Asked how he felt, Homosexual said: ‘A little fatigued.’"] Reference

To activate opacify you need to go to the appearance tab of the preference dialog and check in opacify checkbox.    From Wordnik.com.  [GNOME-Look.org Content] Reference

When opacify is on and you roll over a name in the window list with the mouse, all other windows will become transparent so that you easy can spot the window.    From Wordnik.com.  [GNOME-Look.org Content] Reference

(Perflutren Lipid Microsphere) Injectable Suspension is indicated for use in patients with suboptimal echocardiograms to opacify the left ventricular chamber and to improve the delineation of the left ventricular endocardial border.    From Wordnik.com.  [Digital50.com Digital 50 Daily Industry News RSS Feed] Reference