Comparative Study and Validation of New Methodologies for Measuring Addition

Refraction is the key point of an ophthalmic examination when visual correction is required for distance vision, as is determining the addition for near vision. These measurements can be obtained objectively and/or subjectively.

The addition for near vision is most often obtained using so-called subjective devices, i.e., by relying on the patient's responses.

The state of the accommodative system can, however, be measured objectively using instruments available to prescribers (retinoscopes, automatic refractometers, aberrometers, etc.). These measurements can be used in clinical practice as a solid basis for the initial assessment of the subject's refractive status during a comprehensive eye examination. However, these measurements are not sufficient to determine the optimal correction to prescribe for near vision, i.e., one that achieves sufficient visual acuity and comfort to ensure effectiveness for the tasks a person wishes to perform in their daily life.

Indeed, subjective tests are considered the gold standard for prescribers, particularly when it comes to near vision testing. Also, there are numerous procedures for determining the appropriate addition to prescribe, and a wide variety of practices is observed among prescribers around the world. It is often necessary to perform multiple tests to ensure the correct addition value to recommend.

The aim of this study is to find ways of approaching the value of the ideal addition as accurately as possible, based on several parameters: measurements representative of subjects' near vision habits, optometric measurements to determine near vision addition, and measurements related to binocular vision and symptomatology. This data collection will enable to identify the most effective combination of measurements in order to determine the optimal near vision addition for a subject.

Inclusion criteria

• Volunteer, fluent in French, willing to follow the protocol, able to read and understand the information form and give free and informed consent
• Aged 40 to 60 years
• Individual with monocular visual acuity ≥ +0.1 LogMAR with current corrections and pinhole if necessary
• Individual with a visual acuity difference ≤ 0.2 LogMAR with current corrections
• Individual with stable binocular vision in distance and near vision

Exclusion criteria

• Age < 40 years (i.e., no minors in accordance with Article L1121-7)
• Age > 60 years

All categories of people specifically protected under French law are excluded from this research (Articles L1121-5 to L1121-9 of the Public Health Code):

• Pregnant, childbearing, or breastfeeding women (Article L1121-5)
• Persons deprived of their liberty by a judicial or administrative decision and persons hospitalized without consent pursuant to Articles L. 3212-1 and L. 3213-1 who do not fall under the provisions of Article L. 1121-8 and persons admitted to a health or social care facility for purposes other than research
• Adults incapable or unable to express consent (Article L1121-8)
• Participants currently excluded from another study
• Participants unable to be contacted in case of emergency
• Person with strabismus
• Person with amblyopia
• Aphakic or pseudophakic person
• Person with vertical phoria > 1 PD
• Declared neurological deficit, including a history of epileptic disorders or sensory-motor coordination disorders, vestibular or cerebellar pathology (e.g., balance disorders)
• Declared severe ocular pathology, involving visual field loss, such as glaucoma, or involving loss of acuity and significant discomfort in dimly or excessively lit environments, such as retinitis pigmentosa, or declared and treated dry eye.