Visual fatigue is an extremely common phenomenon, felt at eye level when working for a long time in front of a computer screen or when you have a visual defect (ametropia) that is not corrected or poorly corrected. Reversible, it disappears with rest.
What is the definition of eyestrain?
“Visual fatigue, also known as asthenopiais a condition characterized by a set of ocular symptoms related to prolonged and intense use of the eyes, especially when reading or using digital devices such as computers (intermediate vision with reading at around 70-80 cm), smartphones and tablets (near vision with reading at around 30-40 cm), explains Dr. Didier Hoa, ophthalmologist. “Visual fatigue is mainly manifested by a decrease in visual acuity (the images are duplicated and become blurry and eye irritation with inflammation and feeling of dry eye. The eyes are then red and they itch. Quite easily, visual fatigue is accompanied by a feeling of heaviness behind the eyes or even headaches”. Visual fatigue is often temporary and can be relieved by regular breaks, eye exercises, wearing suitable optical correction and appropriate use of lighting and the screen.
What are the symptoms of eyestrain?
The symptoms of eyestrain can vary from person to person. “But we generally see a general feeling of tiredness or heaviness in the eyes as well as a feeling of dryness, burning, or stinging in the eyes“. There vision may become blurry or cloudy especially at the end of the day. Likewise, a increased sensitivity to bright light or glare can be felt. “Some people may experience difficulty adjusting focus when transitioning between different viewing distances (e.g. looking up close then looking away) or concentrating for long periods of time“. Others may have headaches or frequent headaches, often located around the temples or at the back of the eyes and increased at the end of the day. Finally, among the frequent symptoms of visual fatigue, we can cite pain in or around the eyes and muscle tension often caused by improper posture while reading or using screens.
Visual fatigue and dizziness: why?
Visual fatigue can sometimes be associated with dizziness, although dizziness is not a direct symptom of eyestrain itself. “It can come from muscle tension, resumes the doctor. When the eye muscles are overstretched due to prolonged use of the eyes, they can fatigue and contract abnormally. It may lead to muscle tension in the neck, shoulders, and headwhich can cause dizziness“. Visual fatigue can also affect visual balance, which can disrupt spatial perception and stability. This can cause a feeling unbalanced or dizzy. Finally, when the eyes are tired, they can become more sensitive to bright light or glare. “Exposure to intense light sources may trigger symptoms of vertigo in some people“.
What are the causes of eyestrain?
Visual fatigue can be caused by several factors, the first being a prolonged use of the eyes for activities such as reading, using computers, smartphones or tablets, watch TV, drive long distances or perform detailed tasks. “She can also be related to an effort of accommodation. When you look closely for long periods of time, the eye muscles responsible for accommodation (focusing) have to work continuously, which can lead to eyestrain“. Also in question insufficient or excessive lighting, poor posture as well as an uncomfortable or non-ergonomic position, reflections or poorly adjusted screens or an environment with low contrast. “Dry eye can also be caused by a lack of adequate eye surface lubrication. This may be due to environmental factors such as dry air, air conditioning, heating, decreased tear production or blinking defect (incomplete/abortive blinking or insufficient blinking“. Finally, inadequate visual correction, such as an incorrect eyeglass prescription or ill-fitting contact lenses, can lead to overuse of eye muscles and eyestrain. “Hence the importance of visits to occupational medicine”. It should be noted that visual fatigue can also be associated with other eye or health problems, such as presbyopia, astigmatismbinocular vision disorders or general health problems.
Thanks to Dr Didier Hoa, ophthalmologist and cataract, eyelid and tear duct surgeon at the Clinique du Parc in Castelnau Le Lez (34).