Evaluation of New Head-mounted Visual Aids Among Patients With Low Vision

1. Low vision Low visual acuity refers to a patient who has functional impairment of vision even after treatment or standard refractive correction. The visual acuity of the good middle eye in both eyes is less than 0.3, or the field radius is ≤20°, but still has the ability to use the remaining vision to perform a certain visual activity. In China, low vision caused by eye diseases (such as glaucoma, AMD, RP, DR) can lead to behavioral loss of patients, and standardized rehabilitation treatment of low vision can help 90% of visual impairment patients improve the utilization rate of residual vision, becoming an important way to compensate for the loss of visual function of this group. 2. Visual rehabilitation of low vision The latest definition of visual rehabilitation is a kind of multidisciplinary comprehensive rehabilitation therapy. By ophthalmologists, depending on the light, low vision devices, low vision rehabilitation counselors professional therapists, social workers and psychologists of the multidisciplinary team, using physical, audio, electronic, optical instruments, and life skills training, help patients with low vision to use its residual vision and development skills available to offset the impact of visual impairment in patients, To improve their self-living ability and quality of life. There are three treatment levels: discovery, guidance and referral; Individual rehabilitation; Multidisciplinary visual rehabilitation. The first step of visual rehabilitation is often accurate optometry in order to obtain the best corrected vision, which is also an important basis for the success of visual rehabilitation. On the basis of refractive correction, it can obviously improve the daily living ability and quality of life of the patients with low vision by providing them with appropriate visual aids and corresponding training of using visual aids. Visual aids are generally divided into near-use and far-use visual aids, in which near-vision and reading ability are the focus of functional vision assessment and rehabilitation. Traditional used visual aids have hand-held magnifier, vertical magnifier, glasses and electronic visual aids. Compared with optical visual aids, electronic visual aids have the advantages of clear imaging, adjustable magnification and contrast. 3. Research status of smart wearable devices Traditional visual AIDS achieve the effect of object image amplification through the principle of optics, but have fixed magnification rate, reduced field of vision, small depth of field, short working distance, can not adjust the contrast and other shortcomings. In recent years, video wearable devices have been gradually applied in the field of visual rehabilitation, with the advantages of adjustable magnification, adjustable contrast and high clarity, overcoming the limitations of traditional optical devices, including eSight 3, NuEyes, IrisVision, etc. Currently, there are few studies on wearable electronic visual aids. Walter Wittich et al. conducted an intervention trial on 51 patients with low vision and confirmed that wearable electronic visual aids can improve patients' visual acuity, spatial object recognition ability, and reading and activity ability. In the study of middle-advanced glaucoma, Yogesh Patodia et al. found that wearable electronic visual aids can also improve their long-range and near-range vision. Smart glasses such as Beyes, HOLA, Acesight and OXSIGHT are the latest wearable electronic visual aids to hit the market, featuring advantages of lighter weight, comfortable wearing, better imaging quality and multi-mode assisted visual recognition. However, the effect and influencing factors of this kind of smart glasses on advanced patients with glaucoma, AMD, RP, DR and other common blinding eye diseases are still unclear, which requires further exploration by researchers.