Most computer displays are suitable for use with the Thomson Test Chart  although you should check the following:

Size: The Thomson Test Chart can be used with a monitor of any size. However, the larger the monitor, the larger the letters that may be displayed on it. Other factors to take into account are:

    • Viewing distance -the greater the viewing distance, the larger the monitor required to show letters of a given angular subtense (LogMAR or Snellen size).
    • The nature of the patients to be tested - for example, in a hospital environment it is likely that a high proportion of patients will have poorer visual acuity and therefore a large monitor should be considered.

Over the past decade, the price of large displays has fallen dramatically and it is generally recommended that you choose the largest monitor that your budget will allow.

Note: If you wish to make use of the polarised mask option supported by the Thomson Test Chart , you will require a 24’’ widescreen display. Please contact Thomson Software Solutions for advice on suitable monitors.

Resolution: Since the pixel size on flat panel displays is fixed, the resolution is largely determined by the size of the display. Most 24’’ displays have a resolution of  1980 x 1080 etc.

Viewing Angle: Modern flat panel displays have very wide viewing angles (i.e. the luminance remains constant from a wide range of viewing angles). In the consulting room the display will be viewed from at least 3 metres so this is not a major consideration.

Screen luminance and contrast: Most flat panel displays are capable of producing luminances of 150 cdm-2 or more and contrasts in excess of 200:1. This is perfectly adequate for displaying test charts and meets all relevant standards for test charts.

Screen uniformity. Flat panel displays generally have very uniform luminance across the screen and are very stable over time.

Polarisation. A range of clinical-quality polarised monitors are available from Thomson Software Solutions.  These monitors allow targets to be presented to each eye separately on the screen.  The Thomson Test Chart contains a wide range of tests which exploit this polarised technology.  Please contact Thomson Software Solutions for further details.


27'' Clinical-quality polarised monitor available from Thomson Software Solutions

IMPORTANT

If you want to mount the flat panel display directly on the wall (the neatest solution) check the following:

  • It has VESA compliant fittings (screw holes in standard locations so that a standard wall mounting bracket can be used - available from Thomson-Software-Solutions if required)
  • It has a separate power supply - some models have the power supply built into the base unit