This Wednesday, December 14, 2022 marked the end of a decade of waiting. “Avatar: The Way of the Water”, the second installment of James Cameron’s cult 3D film, has been released in theaters. However, not all viewers can fully experience the magic of three-dimensional Pandora landscapes. In fact, certain visual disturbances make it impossible to see feature films in relief.
- To fully enjoy a 3D film, you must wear your correction (glasses or contact lenses) in addition to the cinema glasses. It is also preferable that the glasses are clean.
- There is no medical reason preventing you from seeing several 3D films in a row. It can just be tiring because of the phoria (small current shift between the two eyes that is naturally corrected through convergence).
- According to estimates, between 3 to 4% of the Western population suffers from strabismus.
Whether it’s blockbuster movies like Avatar 2, science fiction (Jurassic World), superheroes (Ant-Man, Thor, Black Panther), anime (Minion, Disney) or even old reworked hits (Titanic)… 3D feature films are invading cinemas. But the eyes of some viewers do not allow them to immerse themselves in these beautiful images, despite wearing dedicated glasses. Dr. Dedes, ophthalmologist and secretary general of the SNOF (National Union of Ophthalmologists of France), details the eye pathologies that are likely to disturb a film session.
3D films: the lack of binocular vision in question
Seeing Pandora in 3D requires superimposing two images. Thanks to the glasses’ filters, you see one with one eye and the other – which is slightly offset – with the second. This is what gives the feeling of relief. “To see this relief, the two eyes must work perfectly together to achieve the fusion of the image of the right eye and that of the left eye together”. This is the principle of binocular vision. But some individuals do not have it, such as those who suffer from strabismus.
“If you have strabismus, the two eyes can’t work together because they’re looking at different things. So people with this disorder don’t have sharp 3D vision. For them, watching a 3D movie doesn’t have a not much interest. Despite wearing the dedicated glasses, they will see it as if you were watching it while hiding one eye”, says the expert. Patients who have lost an eye face the same problem. They see images in 2D. However, their brain can manage to partially reconstruct certain elements of the dimension by using visual clues present in the field of vision of the valid eye.
Spectators with large power differences between the two eyes are also likely to have difficulty during the session. “They have one eye with standard power and the other not. The images then have different sizes and the brain fails to merge them”indicates the ophthalmologist.
No relief vision: no reason to deprive yourself of the film
Although patients who do not have binocular vision do not take full advantage of the effects of 3D films, they have no reason to deprive themselves of a film session with their loved ones, specifies the expert. “There is no scientific evidence that 3D films can make vision problems worse. It’s a bit tiring for people who have incomplete or imperfect binocular vision. But medically, it’s not going to harm anything.”
“Besides, it’s surprising, but children with strabismus inducing an absence of binocular vision, claim to see a difference compared to standard films. They are generally happy to have seen the film in 3D. there is therefore no reason to deprive them of a session with their siblings or their friends”reassures the secretary general of the SNOF.