'Sun' glasses to help you beat winter blues

Developed by three Danish engineers, these 'sun' glasses bring the daylight inside even on the darkest of days.

They work using six light emitting diodes (LED's) that produce a powerful light field reflected into the eyes by a curved reflector, the 'Daily Mail' reported.

Described as 'a calorie-free, substance-free way' to lighten your mood, the 54 pounds glasses are designed to be worn while you go about your morning routine as they do not obscure your field of vision.

The makers claim wearing the glasses for up to 30 minutes a day will mean "you'll have much more energy during those long, dark winter months".

Seasonal affected disorder (SAD) affects around one in 50 people in the UK.

The main symptoms are a persistent low mood and a marked loss of interests or pleasure in activities.

Fatigue, comfort eating and heavy limbs are other common symptoms, the report said.

The depression usually develops sometime between September and November and continues until March or April. It is thought to be linked to reduced exposure to sunlight and is more common the further you go from the equator.

Light therapy - sitting in front of a special bright light for a time each day - is an effective treatment in many cases.

The light source need to be at least 2500 lux, about 10 times that of ordinary light bulbs.