Viewing a 3D movie at the cinema is beneficial for children with amblyopia or lazy eye. This is the main conclusion of a pilot study conducted by a team of researchers from the Terrassa School of Optics and Optometry (FOOT) and the Centre for Sensors, Instruments and Systems Development (CD6) of the Universitat Politècnica de Catalunya - BarcelonaTech (UPC), and the MútuaTerrassa University Hospital (HUMT).

Pioneering in Europe, the clinical trial was conducted by predoctoral researcher Laura Asensio Jurado and FOOT professors Marc Argilés Sans and Lluïsa Quevedo Junyent at a cinema in Sant Cugat del Vallès in March 2022. The objective was to determine if viewing a 3D movie in a cinema resulted in improved visual acuity, stereoscopic depth perception and ocular alignment in children with refractive and/or strabismic amblyopia.

The participants, 24 children aged 5 to 12, watched a 3D movie for 110 minutes. There were children with a history of anisometropic and/or strabismic amblyopia, who had been previously treated and had residual amblyopia, and also typically developing children without amblyopia. Indicators such as visual acuity, stereoacuity and ocular deviation were evaluated.

The study revealed significant improvements in visual acuity and binocularity, suggesting that “watching 3D movies at the cinema improves visual functions in amblyopia and could offer a viable and potentially effective alternative to conventional treatments", as explained by Laura Asensio, a doctoral candidate in Optical Engineering at FOOT and an optometrist in the HUMT’s ophthalmology service. This study is part of her doctoral thesis, which is being developed in collaboration between the three institutions.

It demonstrates that “exposure to high binocular disparity demands produced by 3D cinema screens stimulates the visual system, which is deficient in amblyopia", according to professor and CD6 researcher Marc Argilés. He adds that “motivation and attention while viewing the movie also play a role".

Towards new treatments for amblyopia in children
Amblyopia is one of the most common causes of visual impairment in childhood, affecting approximately 2-3% of children. This condition results from the interruption in the normal processing of images in the brain, usually due to differences in the quality of the images received by each eye. The most common causes are strabismus (misaligned eyes) and significant refractive errors.

Amblyopia is estimated to affect between 1% and 5% of people globally, although prevalence varies between studies and regions. Early detection and treatment are crucial, especially in childhood, when the brain is still able to reorganise visual connections.

Traditionally, amblyopia treatment involves correcting any underlying problem causing the image quality difference between the two eyes. Patients wear glasses or contact lenses to correct refractive errors and, in some cases, they undergo surgery to correct strabismus. The most well-known treatment is occlusion therapy, in which the dominant eye is patched for several hours a day to force the weaker eye to work harder.

The work of these researchers from FOOT, the CD6 and the HUMT now opens the door to the development of new treatments. The research team are optimistic about the implementation of such new therapies in clinical practice and hope for their work to inspire further studies and advancements in this field.