13. Pros and cons of LEDs

LED as a light signal
Pro	Cons
Can convey simple information e.g. monitor on/off; caps lock on/off	Need to understand what the light signal represents
Inexpensive method of providing information	No use for people with visual impairment
No language barriers	Difficult to see if bright background light or if positioned at the wrong angle
Long life - will probably outlast the equipment	Only able to impart limited information
LEDs light up very quickly.	Concerns that blue and white LEDs are capable of exceeding safe limits of the 'blue-light hazard' and could potentially cause damage to eye sight.
LEDs are very small and so don't take up much space on an appliance	Only able to impart limited information

LED Display Board
Pro	Cons
Easier to keep up-to-date than static textual information	Only limited information can be displayed
Minimal text so more easily understood by people with poor literacy or language skills	Information needs to be regularly updated
Can convey a lot of information in a few words e.g.an LED display at a train station, 'Arrive 12:15 London On-time'	If any hardware, software or network failure the information cannot be displayed
Can display text in a wide range of colours and character heights which can help people with visual impairments	If display is at the wrong angle it might be difficult for some people to read
After initial purchase of equipment, a low cost way to convey information	Can be subject to glare from sunlight. If excessive light is shining on the display it might be difficult to read
Some LEDs are capable of animation so can be used to convey different types of information.	Initial cost of equipment can be high