Understanding the Correlation Between Visual Impairment and Mental Health: Literature Review

Low vision is one of the major ophthalmologic problems and the leading causes of disability in older adults associated with reduced quality of life and increased depressive symptoms. In turn, depression may cause a further decline in quality of life, may aggravate disability caused by the visual impairment, and may increase vulnerability for health decline. Approximately around 36 million are blind, and 217 million have marked moderate to severe visual impairment. Visual impairment refers, generally, to poor vision. Observational data revealed that those with sight loss were twice as likely as those with another impairment to have experienced discrimination. There is evidence that individuals with visual impairment have poorer mental health than their impairment-free counterparts. In health care settings, an association between visual impairment and depression has been consistently reported. Greater prevalence of depressive symptoms in those with visual impairment has also been reported. The aim of this review is therefore to summarize the literature with the goal to untangle the relationship between vision loss and psychological factors that lead to mental health disturbance.


Introduction
Visual impairment is something serious that has been declared by the World Health Organization  Thus, people with age-related vision loss constitute a large percentage of the visual impairment population.
As mental health conditions are already fairly prevalent among older adults, with estimates of major depression ranging from 1-5% in community samples, older adults with vision impairments may be at even greater risk for mental health problems.
Indeed, visual disability has been identified as a strong indicator of depression in older adults.

Low vision, stress, and the brain
There are so many stressors in our daily lives such as challenging life events and any similar other stimuli that can lead to stress. However, in what way the body and mind react to any specific stressor depends on the brain's interpretation and the bodily reaction to it. The brain's appraisal determines

Stress response systems
The brain has two outflow systems to control the adaptation of the body to stress: firstly, the neuronal sympathetic adrenomedullary system (SAM) which is part of the autonomic nervous system, and secondly a neuroendocrine stress response system, i.e., hypothalamic-pituitary-adrenal axis (HPA). Both are activated during stress, and both are controlled by neural brain networks which are involved in the control of stress and emotion. Critical brain regions are the brain stem, hypothalamus, prefrontal cortex, amygdala, and hippocampus.

The relationship between vision impairment and mental health
People with vision impairment may experience mental health difficulties for a variety of reasons.
Included among these is the emotional distress that is associated with losing one's sight. Self-reported reactions to vision loss include anxiety, worry, frustration, social withdrawal, and embarrassment.
Additionally, for individuals with progressive vision loss, substantial fear and anxiety may be experienced in anticipation of further reductions in sight.

Music therapy
Music has been used since ancient times to enhance wellbeing and reduce pain and suffering.
Steady rhythms entrain regular respiratory patterns, and listening to classical music increases heart rate variability (a measure of cardiac autonomic balance), whereas listening to noise or rock music decreases heart rate variability. A meta-analysis indicates that music alone and music-assisted relaxation techniques significantly decreases arousal due to stress. This significantly increased their anxiety, heart rate, and systolic blood pressure. But when they were exposed to music therapy, there was a significant reduc-tion of anxiety by 28%, in systolic blood pressure by 26% and in heart rate by 36%.

Biofeedback
Biofeedback is a method of gaining greater awareness of the body's physiological state using instruments that provide information on the activity of different bodily parameters such as brain wave activity, muscle tone, heart rate, or skin temperature.
The goal is learn to manipulate these functions at will to achieve a state of relaxation. Though biofeedback has been used to improve visual fields in patients, it has so far only been used as a means to induce relaxation in normally seeing subjects. Amore et al.
reported that biofeedback-relaxation can increase finger temperature and cardiac output and decrease systemic vascular resistance and respiratory rate.

Coping strategies
There are different strategies for better coping with medical problems. They include cognitive restructuring such as optimism (looking not only at the rear mirror but looking forward), looking at the situation in relative terms such as "there are so many worse things" to keep vision loss in perspective. There are also more general methods to help with emotional anger including psychotherapy or even simply "kicking and screaming"

Social support
Decreased visual acuity, visual field loss, or blurred "foggy" vision are also associated with decreased QOL. Family members can play an important role in the adaptation of patients, providing encouragement for the initiation and completion of rehabilitative services. In Reinhardt's study, scores for support by family members were higher than those for friend. As compared to friends, family members are relied upon more often for both instrumental (practical) and emotional support.

Conclusion
For the conclusion, vision loss reduces subjective QOL due to anxiety, fear, and depression, i.e., stress being the consequence of low vision. On the otherhand mental stress is also a predilection of visual disease. Stress leads to vision loss which causes stress, which in turn worsens the vision loss, making the stress even worse and so on. Mental stress which classified in vision-specific distress might be related to depression via a reduction in social connectedness and ability to engage in pleasurable activities. Even worse, the thought of invaluable self makes the person with visual imparment fall deeper with depression. Visuallyimpaired population as high-risk group should be provided better access to mental health care, which can promote early detection of mental disorder and provide prompt treatment for low-vision patients with depressive symptoms.