What are typoscopes, video magnifying glasses, filters, telemicroscopes and apps for people with low vision? How are they used?

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There are various devices that can help people with low vision make the most of their residual vision

After the different diagnostic tests the specialist is responsible for offering the patient the different alternatives according to their needs and objectives:

Optical aids such as magnifying glasses, microscopes or filters enlarge the image formed on the retina

This is a set of lenses or lens systems that can be adapted for use as glasses or manually, which usually enlarges the image formed on the retina. The most common devices are:

  • Magnifying glasses. A simple, popular and easy-to-use system. They are lenses that increase the size of objects and allow the performance of specific proximal vision tasks that require a small visual field, such as reading, consulting prices, following receipts, etc. They can be manual, with support, fixed focus, focusable, with light, pocket, etc.
  • Microscopes.Lenses that allow patients to see objects at short distances. Unlike magnifying glasses, they leave both hands free and the visual field is wider, making them more comfortable during long periods of reading, writing, sewing, etc. They can be monofocal, bifocal, trifocal or multifocal, to switch between near and distant vision, according to the needs.
  • Telescopes.Devices that enlarge and bring the image of distant objects closer. They can be attached to glasses permanently in the central or upper position.
  • Telemicroscopes. They combine an upper microscope and a lower microscope fitted to the same lens to allow both near and distant objects to be viewed.
  • Filters. Recommended to control glare, produce contrast and adapt to light, as well as to improve the patient's visual acuity. They may be organic or mineral, polarised and photochromatic.

Non-optical aids optimise the patient's residual vision without the need for optical lenses or systems

They optimise the patient's residual vision without the need to use optical lenses or systems. They are used to improve posture, contrast, lighting or working distance.  Depending on each patient's objectives, use can be made of all kinds of lecterns, typoscopes (a black card with a groove that is moved over the text you want to read), macrotypes (an ink printing system with large characters), fluorescent light lamps, spectral control lights (LED), high-contrast papers, cooking utensils adapted for low vision (such as transparent glass saucepans to see the water boiling), speaking watches, phones with large keys, location lights, restraining and balancing supports, mechanical sewing machines, calibrator purses, etc.

Video magnifying glasses, typoscopes, intelligent apps, etc.; electronic aids to increase the image size

A set of devices for near vision that increase the size of the image through electronic means. This group includes closed-circuit television integrated with an electronic digital magnifier that scans the pages and increases the size of the letters and changes the contrast (white letters on a black background or black letters on a white or blue background, etc.). They can be adapted to any television and certain models facilitate writing. Other electronic systems are portable desktop video magnifying glasses (with a microcamera that, when connected to the television, shows text in a larger font), digital zooms and computer applications and intelligent phones that include the magnifying-glass effect or voice system to improve their usability.

Visual rehabilitation: support and guidance on proper use of the aids

With the aim of making the most of their residual vision, the patient with low vision should receive training on how to use the visual aids, as well as guidance and advice on mobility and skills to apply to everyday tasks, such as cooking, ironing, using money, using the phone, tidying the house, etc. This rehabilitation is carried out at all times under the supervision of the low vision specialist and aims to try and restore deficiencies the patient experiences on a daily basis.

The patient receiving the necessary support and guidance for proper use of the aids is a very important process. In addition, during the training, the specialist acquires better knowledge of their patient needs, since during this period the latter's concerns and aims are shared more spontaneously. A process that also gives the patient time to learn and respond during their active participation in rehabilitation. As far as possible, it is best that the patient receives regular follow-ups allowing the specialist to assess the improvement achieved and to avoid any deterioration or visual relapse.

IMO's Low Vision Department helps to improve patients' quality of life

At present, there are very few low vision departments in Spain and there is still a lack of awareness of this specialty. According to the optometrist Carol Camino, “many patients that come for a consultation are surprised about what can be done to improve their vision and wish they had known sooner."

The specialist is in charge of the Low Vision Department at IMO, which helps people with a visual deficit to make the most of their residual vision, so they can continue with their daily activities and substantially improve their quality of life. Carol Camino has an Optics Degree from the College of Optics at the Polytechnic University of Catalonia, a Degree in Optics and Optometry from the College of Optics and Optometry from the Faculty of Sciences at Granada University and a Master's Degree in Clinical Optometric Sciences, Low Vision Specialty, from the Pennsylvania College of Optometry (Philadelphia, USA). She also works with IMO on the "Ven y Verás" (Come and See) days for the Abre sus Ojos Foundation, whose aim is to improve the visual health of disabled people.

Helpful hints to get on better in the everyday environment

There are a series of general recommendations that allow people with low vision to get on better in their everyday environment:

  • Always keep furniture and household utensils in the same place
  • Paint frames and edges of doors and windows in well-contrasted colours
  • Mark the edges of stairs, balustrades and steps
  • Use coloured crockery and kitchen utensils for better contrast
  • Use glass ceramic or induction cookers. If cooking with gas, avoid using matches and opt for a lighter
  • Avoid mirrors with reflected light that may cause glare
  • Avoid using shiny tiles in bathrooms and kitchens
  • Create shaded areas with blinds or curtains
  • Watch TV without the light on
  • Place signs at eye level
  • Wear sun visors
  • Use lined paper so as not to lose your place when reading or writing
  • Write with thick black felt-tip pens

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