Many people on the autism spectrum have difficulty processing everyday sensory information that most neurotypical people take for granted.  Any of the senses may be over or under-sensitive, or both, at different times. These sensory differences can affect our behaviour, and can have a profound effect on a person’s life.

Sometimes an autistic person may behave in a way that you wouldn’t immediately link to sensory sensitivities. A person who struggles to deal with everyday sensory information can experience sensory or information overload. Too much information can cause stress, anxiety and sometimes physical pain. This can result in withdrawal, challenging behaviour or as a worst-case scenario, a meltdown. These issues and senses are as follows, but not limited to:-

SIGHT

Under-Sensitive

•  Objects appear quite dark, or lose some of their features.
• Central vision is blurred but peripheral vision quite sharp.
• A central object is magnified, but objects on the periphery are blurred.
• Poor depth perception; problems with throwing and catching; clumsiness.

Things that might help include the use of visual supports or coloured lenses, although there is very limited research/evidence for such lenses.

Over-Sensitive

Distorted vision

•  Objects and bright lights can appear to jump around.
• Images may fragment.
• Easier and more pleasurable to focus on a detail rather than the whole object.
• Difficulty getting to sleep as sensitive to the light.
• Light hurting your eyes or causing headaches

SOUND

Under-Sensitive

• May only hear sounds in one ear, the other ear having only partial hearing or none at all.
• May not acknowledge particular sounds.
• Might enjoy crowded, noisy places or bang doors and objects.
  You could help by using visual supports to back up verbal information, and ensuring that other people are aware of the under-sensitivity so that they can communicate effectively. You could ensure that the experiences they enjoy are included in their daily timetable, to ensure this sensory need is met.

Over-Sensitive

•  Noise can be magnified and sounds become distorted and muddled.
• May be able to hear conversations in the distance.
• Inability to cut out sounds – notably background noise, leading to difficulties concentrating.

SMELL

Under-Sensitive

•  Some people have no sense of smell and fail to notice extreme odours (this can include their own body odour).
• Some people may lick things to get a better sense of what they are.

Over-Sensitive

Smells can be intense and overpowering. This can cause toileting problems.
Dislikes people with distinctive perfumes, shampoos, etc.

TASTE

Under-Sensitive

•  Likes very spicy foods.
• Eats or mouths non-edible items such as stones, dirt, soil, grass, metal, faeces.
• This is known as pica.

Over- Sensitive

•  Finds some flavours and foods too strong and overpowering because of very sensitive taste buds. Has a restricted diet.
• Certain textures cause discomfort – may only eat smooth foods like mashed potatoes or ice-cream.
• Some autistic people may limit themselves to bland foods or crave very strong-tasting food. As long as someone has some dietary variety, this isn’t necessarily a problem. Find out more about over-eating and restricted diets.

TOUCH

Under-Sensitive

•  Holds others tightly – needs to do so before there is a sensation of having applied any pressure.
• Has a high pain threshold.
• May be unable to feel food in the mouth.
• May self-harm.
• Enjoys heavy objects (eg weighted blankets) on top of them.
• Smears faeces as enjoys the texture.
• Chews on everything, including clothing and inedible objects.

You could help by:

•  For smearing, offering alternatives to handle with similar textures, such as jelly, or cornflour and water.
• For chewing, offering latex-free tubes, straws or hard sweets (chill in the fridge).

Over-Sensitive

•  Touch can be painful and uncomfortable – people may not like to be touched and this can affect their relationships with others.
• Dislikes having anything on hands or feet.
• Difficulties brushing and washing hair because head is sensitive.
• May find many food textures uncomfortable.
• Only tolerates certain types of clothing or textures.