Was in Tesco Opticians for Kids glasses and found How to Train Your Dragon 2 goodie bags with 3D glasses. They have Children and Adult glasses, designed for better fit over normal glasses.
Also good for Passive 3D TVs eg LG.
From Tesco's website:
To celebrate the release of How to Train Your Dragon 2, Dreamworks have teamed up with Tesco Opticians to bring Dreamworks’ official How to Train Your Dragon 2 3D glasses to Tesco Opticians stores! Available in child and adult sizes, How to Train Your Dragon 2 3D glasses will enable you to enjoy the full 3D experience of the film in all its fire-breathing glory! Collect your glasses from Tesco Opticians stores from 26th June* and prepare yourself for a magical adventure when How to Train Your Dragon 2 hits cinemas 4th July.
*The 3D promotional glasses are available at the Opticians department in stores only from June 26th, whilst stocks last. One pair per customer, available on a first come first served basis. Tesco Opticians are not liable if the promotional product is not available for any reason. To find a participating store click here. Products have no cash value and cannot be exchanged for goods or services.
Promotional glasses are passive 3D glasses and have been designed for theatrical projection shown in stereoscopic 3D. Please note the 3D glasses are not prescription glasses and are not to be used for any other activities other than for use when viewing a 3D film in a cinema. They are not safe for use as sunglasses, these glasses do not protect your eyes from ultraviolet light. Keep out of reach of children under the age of 3.