Earlier in the year, Professor David Thomson wrote a two-part CET series looking at the evolution of acuity testing and charts. In the second of these (see Optician 10.09.21), he mentioned the Vision Toolbox from his company Thomson Software Solutions.
In recent years, I have been taking my laptop around with me on domiciliary visits and find the Test Chart 2020 electronic acuity charts more reliable and adaptable than hand-held charts. Increasingly for near vision assessment, I had starting replacing near cards with my tablet and running apps such as the Kindle app to assess near function. The variation of font size, design and the ability to change the viewing contrast colours are helpful, but I have always worried about the accuracy of target size interpretation. So, recently, I finally got round to trying out Thomson’s Toolbox.
Vision Toolbox
The app has a comprehensive range of test charts and stimuli, along with a miscellaneous range of calculators and patient information resources. This explains the 600+ MB memory required to run the app, so not one for older tablets of lower specification. The various features can be categorised into four main types:
- Near tests; the app exploits the graphics capability of the iPad to provide a huge range of near vision test and charts (a range of near target examples is shown in figure 1)
- Three-metre tests; these are ideal for domi use and include logMAR charts, single and line acuity, duochrome, cross-cylinder targets and a car registration plate simulation (see figure 2)
- Patient information; the app includes an array of images and videos that are useful when explaining findings to a patient. I found myself using an image of a cataract (attributed to Trevor Warburton) to explain cataract to my patient (figure 3). The videos are of simple concepts, such as the main ametropia types and cataract, but useful nonetheless.
- Toolkit; this section includes a visual acuity converter, logMAR scorer, vertex distance and transposition calculators and a toric contact lens over-refraction calculator.
As a comprehensive battery of near and three-metre test targets that can all fit onto a single tablet, the Vision Toolbox is a useful addition to the domiciliary kit and a significant aid for those with muscles stretched by lugging around heavy kit for home tests.
- The Vision Toolbox is available at the App Store for £49.99.