The invite-only Google Glass Explorer Program is about to be made available to everyone in the US for a very limited period of time.

Open enrollment in Project Glass begins on April 15 and it's expected to last a mere 24 hours, according to an official Google+ announcement by the search engine giant.

Google plans to open up "some spots" to US adults starting at 6 a.m. PT next Tuesday. It'll be a first come, first serve process.

Previously, the only way to purchase Google Glass has been through the official wait list or via a Glass-owning friends' invite code.

A sale in name only

This doesn't give wearable tech wannabes much time to prepare their bank funds. Google Glass will still cost $1,500 (about £893, AU$1,592) plus tax.

Buying Google Glass through these means is not much of a "sale" at full price. However, it does come with one extra that current beta testers have to buy separately.

A free sunglasses shade or prescription glasses frame comes with the wider Google Glass rollout, according to leaked documents obtained by The Verge.

This is a good sign in the lead up to the Google Glass consumer edition expected later this year, which could bring about an even better deal via a lower price.