Imagine you’ve just been told by your eye doctor that you are going to lose your vision to an irreversible and incurable disease – what do you feel? Panic, stress, anxiety, feelings of being overwhelmed, powerlessness, hopelessness, fear? Probably all the above to some degree or another. These feelings may often persist for many patients diagnosed with a progressive sight-threatening condition, beyond the initial breaking of the bad news. You don’t have to stretch your imagination much further to figure that living with a visual impairment can take a toll on an individual’s mental health.

We often take our vision for granted and don’t take time to consider just how much we rely on this sense – driving to school or work, watching movies, reading this article, observing a sunset, detecting subtle facial cues or body language, performing basic tasks in your workplace, and avoiding that huge crack in the sidewalk – if we had to rank our five senses from most to least devastating to lose, vision would definitely be up there. (Of course, all five senses are important from a social and survival perspective and an ongoing debate amongst scientists is actually leaning to the sense of touch, or “somatosensation” as being the leading candidate here – but still, between vision and smell, would you rather smell your little brother approaching or see him instead?).

Current statistics from the World Health Organization (WHO) tell us that around 1.3 billion people around the world live with some form of vision impairment, with 217 million classified as moderate to severe visual impairment and 36 million individuals blind. Under these statistics WHO also included avoidable (and treatable) causes of vision impairment, such as uncorrected refractive errors and cataract, but for an individual living in a low-income country with little or no access to eyecare these conditions may as well be akin to permanent vision loss. The majority of those individuals with visual impairment, whether reversible or otherwise, are aged over 50 years and the number of cases of vision loss is expected to rise in the coming years with an aging global population. Within the next year, the number of people projected to be blind is predicted to increase to 38.5 million.

 
Vision loss and quality of life
WHO gives us an idea of the concept of quality of life (QOL) – “an individual’s perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards, and concerns.” Various questionnaires have been developed to assess and monitor QOL in different situations and for different diseases. An important component of QOL is an individual’s health status, defined by good ol’ WHO as “a state of complete physical, mental, and social well-being, not merely the absence of disease.” Multiple studies have established the effect of vision impairment on reduced QOL, further finding that the severity of the vision loss is directly correlated to a poorer QOL score. At a basic level, QOL is expected to be impacted by visual impairment due to its negative effects on social interactions and independence. Understandably, being unable to drive yourself around may significantly affect your social life, as would difficulties in personal grooming.

The effects of visual disability on QOL vary across communities, cultures, and location. For example, a developed country that is well adjusted to catering for the visually impaired with employment opportunities, workplace laws, and readily accessible low vision aids and services is expected to have visually impaired individuals who score higher on QOL than a blind person living in a country struggling with poverty.

 
Vision loss and depression
Much of the research performed into the impact of vision impairment on depression and anxiety has focused on the elderly as this is the population with the highest prevalence of vision loss. Rates of depression and anxiety are significantly higher in older adults with a visual impairment than their age-matched counterparts with another chronic disease, such as heart conditions, hypertension, or chronic bronchitis.

Children and adolescents are not immune to visual impairment either, whether from eye disease or an unmet need for corrective glasses. Poor vision is associated with poor academic performance, which has been found to be linked to anxiety in school-aged patients. Research into a link between visual disability and suicide found that there was no direct correlation; however, the results suggested that the risk of suicide may be greater in the visually impaired due to lower self-assessed general health and this association with visual disability.

The presence of visual loss has also been found to amplify the effect of other illnesses, further magnifying the difficulties of basic tasks already impacted by the initial disease. One study investigating this phenomenon found that an elderly patient with visual impairment was almost three times more likely to have a moderate to severe limitation in their ability to socialize compared to a patient of a similar age with no visual impairment, but a patient with both visual loss and depression had increased difficulty in maintaining socialization of almost 24 times that of someone with neither of these conditions.

It should come as no surprise that visual impairment and its far-reaching negative effects into daily life and overall satisfaction in life has the potential to make someone feel pretty blue.

 
The effect of mental stress on vision
Interestingly, it has been pointed out that the psychological stress induced from vision loss also has the potential to further aggravate the existing eye disease. The hormone cortisol increases as a response to stress, affecting both the neural and vascular systems of the body. As the eye is technically an extension of the brain and largely comprised of neural tissue while also requiring a healthy blood supply to the optic nerve and retina for vision, impaired regulation of these systems has the potential to contribute to eye diseases such as glaucoma.

Face it, no one really wants to hear this – you’re stressing out from being told you’re losing your vision to an irreversible disease and then you’re told that stressing out is accelerating the relentless progression of your irreversible disease – it’s not a pleasant situation. However, being aware of this vicious cycle may present us with some useful adjunct treatments to use alongside traditional ophthalmology. Relaxation therapy, counselling, and meditation techniques are not only helpful to avoid completely “losing it” (your sanity) but also may help to slow losing “it” (your vision).

Anyone facing visual impairment from any cause should not have to deal with it alone. Your eye doctor is a good first point of call for support as they explain your eye disease, its treatment and prognosis, and should be able to direct you to specialized supportive services such as low vision aids. Being open in seeking help from friends, family, and professional counsellors may also help to ward off nasty situations such as depression and social isolation, and hopefully give your quality of life a good boost.

References
What is the best sense? Scientists are still battling it out. http://theconversation.com/what-is-the-best-sense-scientists-are-still-battling-it-out-113598
Blindness and vision impairment. https://www.who.int/news-room/fact-sheets/detail/blindness-and-visual-impairment
Global causes of blindness and distance vision impairment 1990-2020: a systematic review and meta-analysis. https://www.thelancet.com/journals/langlo/article/PIIS2214-109X(17)30393-5/fulltext
WHOQOL: measuring quality of life. https://www.who.int/healthinfo/survey/whoqol-qualityoflife/en/
The impact of visual impairment on quality of life. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5347211/
Making eye health a population health imperative: vision for tomorrow. 3 The impact of vision loss. https://www.ncbi.nlm.nih.gov/books/NBK402367/
Mental stress as consequence and cause of vision loss: the dawn of psychosomatic ophthalmology for preventative and personalized medicine. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5972137/