Word to describe quality of being a blind study

I'm writing an application that deals with blind studies. What would be the correct term to use when describing whether or not a study is blind? No matter which word I use it always ends up sounding awkward so I'm wondering what the correct term would be.

• Blindedness
• Blindness
• Blind
• Masked (?)

I am also looking for the opposite words, for example, is it correct usage to describe users as "blind/unblind" or "blinded/unblinded"?

In light of the conversation I had this afternoon with my former boss, who actually conducts double- and single-blind studies, here is my revised answer. He also recommends using the specific type of blind experiment you employed.

In this single-blind study, a sample of fourteen participants tasted Coke and Pepsi.

Eighteen students participated in a double-blind study that compared apples and oranges.

It is unusual to describe users as blind (unless they are visually impaired). It would be more common to describe the trials as blind.

The participant completed a practice session, followed by a block of ten blind trials.

Otherwise, it is an open experiment (or open trials).

In a series of open trials, participants first ran to the water fountain and then were required to walk backwards while counting to fifty-seven by eights.

However, it is correct to say "blinded participant" and "blinded experimenter" provided that the context makes it clear that you are referring to the experimental paradigm and not the person's vision.

"Unblinded" can be used to describe someone who has knowledge of the experimental conditions, but it would be more likely to be used for someone who was "blinded" prior to the conclusion of the experiment than for someone who arranged the conditions during the experiment.