What are low vision aids used for?

Low vision specialist

Professor Sanchez talks about low vision and the new developments presented at the IX Conference of the Association of Professionals for the Rehabilitation of People with Visual Impairment (ASPREH), held in Barcelona from May 19 to 20.

Visual impairment implies the presence of an underlying pathology (visual or systemic) that will cause a decrease in visual abilities (visual acuity, visual field, contrast sensitivity, color vision, ability to resolve glare, ability to discriminate in poor lighting conditions, etc.).

To explain the different levels of visual acuity/impairment, it is necessary to indicate beforehand that this is determined by two parameters: visual acuity (level of blur, where from 1 to 10, 10 represents the best vision) and visual field (the “slice” of field that the patient is able to see).

In the absence of specific studies, extrapolating data from the WHO study [Resnikoff, 2004], it is known that 1.46% of the European population suffers from low vision, this would lead us to think that in 2016, almost 700,000 people in our country would suffer from low vision. Bearing in mind that there are currently 72,256 ONCE affiliates, it follows that more than 600,000 people with a visual deficit that undoubtedly leads to varying degrees of visual impairment are without tutored / guided care.

What do we achieve with these visual aids?

These aids provide more comfort, some examples are: electronic magnifiers, television, closed-circuit television, etc. In addition, they provide considerable magnification while maintaining normal reading distance.

What is diagnostic low vision?

Low vision is suffered by people who have difficulties in their daily life due to alterations in their eyesight that can become limiting. They usually have a visual acuity equal to or less than 0.3 or a visual field loss of less than 20 degrees.

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Who is a low vision patient?

Visual acuity must be equal to or less than 0.3 (30% of vision) and visual field equal to or less than 20º. The loss affects both eyes, but there is still a useful visual remainder. Low vision is not a disease and therefore has no cure, it is an irreversible process.

Eleven low vision

When we bring something close to our eyes, the corresponding image is also magnified on the retina. The disadvantage, for example in reading, is the impossibility of the human eye to visualize an object clearly when the distance is so short, limitations that become more acute with age. To alleviate this, the aid of lenses is required.

It is produced when images are projected on screens: cinema, slides… In low vision, closed circuit television (CCTV), also known as television magnifiers, are a clear example of this type of magnification.

To obtain optimum performance with these magnifiers, the focus point must be accurately located, which in the case of manual magnifiers must be done by moving the magnifying glass away from and towards the text.

Also called microscopes, they achieve magnification by “distance reduction”, which occurs when we reduce the distance from the object to the eye. In fact, they do not actually magnify anything by themselves, but they facilitate accommodation, which is the visual function that allows us to get closer to the object to see it clearly.

What are the optical aids?

– Optical aids: these are optical systems consisting of high-powered lenses that help people with impaired vision to make the most of their remaining vision. For distance vision, the only instrument currently used in visual rehabilitation is the telescope.

What are optical aids?

The -Technical or Optical Aids- are instruments, ophthalmic lenses, contact lenses and optical devices individually designed and set up for each patient with ‘LOW VISION’. … With the optometric prescription, the visual acuity of the rest of the vision is improved and blur is reduced.

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How does a person with low vision see?

These patients have visual acuity problems, loss of their central or peripheral vision, blurred, blurred or distorted vision, glare and light adaptation problems.

How to improve low vision

They allow to improve distance vision, for example, to see the TV or the name of a street. They can have different magnifications and can be mounted on glasses for ease of use or for occasional use, with a manual clip or hanging around the neck.

Also called magnifying glasses, they facilitate close-up vision with a wide range of magnifications. They have the advantage of being mounted on a spectacle, leaving the hands free and allowing to observe at the same time a large amount of text. They are ideal for continuous reading and facilitate the vision of both eyes at the same time, they can even be combined in the form of bifocal for distance and near vision. They have the disadvantage of having to get very close to the text.

The electronics incorporated in low vision aids allow access to information on a computer screen or TV with a large magnification of characters, changes in font size, different background colors and text, which facilitates reading or writing for people with low vision.

How do people with low vision see?

Many people with low vision have apparently healthy eyes and eyesight. It is also common for them to function normally at times, while at others they may need assistance or a white cane.

What is low vision disability?

This type of disability is shown by a total or partial visual impairment. The visual field (space visible with the gaze fixed on a point) and visual acuity (ability of the eye to perceive objects) must be taken into account.

What is a visual aid in the industry?

Equipment visuals” include a wide variety of visuals for specific machines and tasks to help improve the efficiency and effectiveness of human interaction with equipment. These visual cues serve as reminders of warnings: They communicate process or procedure settings.

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Optical aids for macular degeneration

– Loss of central vision: the patient may experience a loss of vision that prevents him from reading, watching television, recognizing people’s faces, but does not make mobility impossible. This happens to those who suffer from age-related macular degeneration.

The team specializing in low vision will perform a study to evaluate the vision of each patient. From this, visual acuity, contrast sensitivity, visual field and color vision will be determined.

When the ophthalmologist has diagnosed an eye disease (AMD, glaucoma, inoperable cataract, etc.) that prevents us from performing daily tasks at a distance or up close, and that with conventional optical solutions (glasses, contact lenses, etc.) we are unable to improve. In many occasions it will be the ophthalmologist who will recommend this visual rehabilitation.

All those people with marked vision impairment who are motivated and interested in continuing to perform their usual activities and are willing to work to achieve it can improve their condition significantly with different adaptations and optical aids, customized optical systems and non-optical aids.