Change background colour: 


About 15% of the GENERAL POPULATION suffers from Scotopic Sensitivity Syndrome together with or separate from dyslexia. These individuals suffer from:

  • Slow reading rate
  • Inefficient reading
  • Poor comprehension
  • Inability to read for a length of time
  • Eye strain or eye fatigue
  • Difficulty judging distance
  • Headaches
  • Eye strain when using a computer monitor

Common Characteristics

What are the clues to look for when Scotopic Sensitivity Syndrome is suspected? (Only some of these will apply to any individual.)

General Characteristics

  • Reads in dim light
  • Bothered by glare
  • Light sensitive
  • Red and/or watery eyes


  • Headaches
  • Burning, scratchy or itching eyes
  • Falls asleep when reading
  • Words double, move or look fuzzy
  • Words are blurry or fuzzy
  • Words disappear

Observations While Reading

  • Rubs eyes
  • Moves closer to or further from the book
  • Excessive blinking or squinting
  • Must incorporate breaks into reading
  • Moves book to reduce glare
  • Moves head or reads close to the page
  • Reads word by word
  • Uses fingers or other marker

Types of Reading Difficulties

  • Skips or substitutes words
  • Repeats or skips lines
  • Cannot read for long
  • Loses places
  • Reading is slow and hesitant
  • Reading skills and comprehension deteriorates as reading continues

Complaints on Computers

  • Eye strain and fatigue and headaches


  • Writes up or down hill
  • Unequal spacing between letters and words
  • Inability to write on the line
  • Makes errors copying from books or blackboard
  • Squints or blinks while copying from blackboard

Depth Perception

  • Difficulty getting on and off escalators
  • Clumsy
  • Walks into table edges or door jams
  • Difficulty judging distance
  • Drops or knocks thing over

*Note: Please go to "Observation Form" and print out a more complete list of symptoms.

Last modified on October 9, 2014


More info pic

AAIC - Australasian Association Irlen Consultants