Posture defines the physical position of the body in the space. It depends by the complicated system of postural reflexes, given by the central and peripheral nervous system; they involve feet, ears, skin, muscles, joints and eyes. Numerous researches study connections between vision and postural systems. At the Santona Optic Centre, you can have specific exams to verify, in collaboration with other professionals for postural problems, if your own vision problems are related to postural ones. It is a deeper multidisciplinary approach, which considers relations between vision and posture: even vision has a role in keeping balance and normal posture.
Posture and proximal effort
Various work activities obligate the eyes to a close distance while the body is in a static posture: student at school, employees at office, technicians checking pieces… This means a long effort, which can give annoying symptoms. Different researches got deeper on reducing vision efforts and postural issues given by a long proximal activity. These studies gave solid indications, useful in prevention.
Here is a summary:
- Optimal reading and writing distance is that one between the elbow and the first phalanx of the middle finger. It is known as Harmon Distance and corresponds to about 35/40 cm in adults and about 25/30 in children.
- In order to keep a correct Harmon Distance, you should read using an inclined plane (sage for reading and rigid support for writing) with an inclination of about 20°. The sage ensures, with a correct distance between eyes and work plane, the maintenance of an appropriate posture of your back, neck and shoulders.
- The worktable must have a functional highness to the individual stature, so the chair should be regulated in an appropriate way, checking that your feet are comfortably leaned on the floor. The chair should be regulated in order for the lumbar contact to reduce the load on the spine and for the seat (better if with a concave shape) to give an appropriate distribution of the body weight.
- In order to reduce vision efforts, you should modulate the light on your worktable and environment, to avoid annoying reflexes. While you are writing, the source of light must be opposite to the used hand, so that you can avoid shades on the paper and the consequence of abnormal postures trying to see what you are writing.
Posture and optic correction
The synergy between vision and postural system is very important and must be considered if you need an optic correction. The compensation of a vision problem with ophthalmic lenses gives variations in vision perception that often have an impact on posture. These perceptive modifications, which need a first phase of adaptation, can be explained with physical laws of Optic and they occur all the time, even when glasses have been well realized. They include a variation of size of the retinal image, a prismatic effect in lateral vision (when the vision axis does not match with the optic axis of the lens), a variation of the peripheral vision field, and an alteration of ocular movements. Perceptive modifications generally consist in minor diseases, that get worse when glasses are not well centered, which means that lenses have not been climbed on in correct position in front of the eye; in this situation, their optical center is not exactly at the pupil center, in horizontal or vertical meaning. In case of specific postural problems, at the Santona Optic Centre we do vision-postural exams opportunely integrated with the traditional visual tests. It is so possible to identify the best optic solution, a correction that guarantees comfort and good vision acuity but also control and maintenance of a correct posture. The professional team of Santona Optic Centre also gives essential advices for the choice of frame and ophthalmic lenses, guaranteeing the correct realization of the glasses and, in some cases (anisometropia, irregular astigmatism, and high ametropia), by recommending the use of contact lenses, more appropriate to protect the postural balance.