INTRODUCTION

Aging is a global phenomenon. By 2030, 55 countries are expected to see people aged 60 and over make up at least 20 percent of their total populations. There are more people aged 60 and older than the entire populations of Russia, Japan, France, Germany and Australia combined. Worldwide, there are 800 million people aged 60 and above. By 2020, the global populations for 60 and older is projected to be 1 billion and by 2050, the number of people age 60 and older will double to 2 billion with more than 1 in of 4 people aged 60 and older in Europe, USA, and China. Population aging not only brings forth new challenges but also some new opportunities. Current research on aging populations reveals that the majority of the seniors are comfortable with aging, are leading healthier and happy lives, have a positive attitude and enjoy a busy life engaged in both indoor and outdoor activities.
Therefore, it is evident that society needs to provide a variety of services in order for populations to age with a good quality of life.

VISION ISSUES AMONG YOUNG AND MATURE SENIORS

A recent survey from IPSOS – 2011 [1] has shown that seniors report vision issues mainly related to light conditions; approximately 60% of the respondents (in the age group of 60 and above) interviewed acknowledged experiencing vision problems such as near vision difficulties in low light conditions, sensitivity to bright light or problems with night vision. Even with a good pair of corrective eyeglasses they encounter some
discomfort. Several respondents mentioned difficulty in reading small print, for instance, reading instructions for use on medicines. Many seniors also mentioned discomfort in reading due to low contrast, for example, reading print on coloured backgrounds in magazines.
Additionally, most of the 60+ population admitted to experiencing sensitivity to sunlight in the outdoor environment, and 17% of this age group also affirmed to have been bothered from outside glare. These symptoms are even higher when considering people who have cataracts: before surgery, over 75% of the seniors suffer from several of the above mentioned vision issues. Cataract surgery alleviates some of these problems, but light sensitivity is still an uncorrected problem and the mature age group, in an attempt to protect their eyes, end up wearing sunglasses to lessen the adverse effect of light on their eyes.

PHYSIOLOGICAL CHANGES DUE TO AGING

Even though presbyopia stabilises at the age of 60, physical changes can occur in almost every organ and can affect seniors‘ health and lifestyle. Overall, the changes in later life entail a general slowing down of all organ systems due to a gradual decline in cellular activity. Along with a variety of physiological changes that accompany the aging process, changes in the sensory (vision, hearing, skin sensitivity, taste and smell) also occur [3]. About 65% of all people who are visually impaired are aged 50 and older. With an increasing elderly population in many countries, more people will be at risk of age-related visual impairment [14]. Although visual impairment can be linked to neural
losses, the major decline is due to changes in the eye‘s optics [9, 13]. In general, visual acuity decreases with age (from 10/10 to 6/10 from 65 to 90 years). This decrease is even more significant when the contrast is low [10]. Indeed, the difficulty of reading in low light expressed by the elderly is associated with a decline in spatial contrast sensitivity. Retinal luminance in older eyes is reduced due to pupillary miosis and the increased density of the crystalline lens [4, 9]. There is also an increased intraocular light scatter and increased optical aberrations during the aging process [12].

Fig. 1: Intraocular light scatter.

Some studies also report that with aging, neural cell density declines. By age 60-70 years old, the density of rod photoreceptors and ganglion cell decreases dramatically in the peri macula. Older adults require on average three times the contrast of younger adults in order to determine a target. Although major discomfort reported by seniors is the loss of visual performance in low light, the first sign of retinal aging is the time it takes for dark adaptation of the peripheral retina [6]. This scotopic sensitivity loss is due to the slowed photopigment regeneration (rhodospin). Older people feel more difficulty to adapt to changes in brightness and this explains, the difficulties associated with night driving. Visual performance declines during the time it takes for the retina to process visual acuity, contrast sensitivity, attentional field and motion perception are considerably slower to adapt [7, 9]. With no available remedy to these problems, elderly people simply avoid night driving. On the other hand, the presence of too much light also strongly penalizes the visual comfort of the elderly [8]. This time, the decrease of the time regeneration of the cone visual pigment (called opsine) of the central retina affects the recovery time in light [11, 2]. The retina gets flooded with light which leads to a dazzled effect on the eye, associated with several types of discomfort such as pain, loss of contrast sensitivity and visual acuity. Time to visual recovery depends on the age and on the duration of time exposed to light. Natural aging affects several visual functions which adversely impact the day-to-day life activities for an individual. It is also important to note that the presence of visual pathology, such as cataract, age related macular degeneration and glaucoma, will amplify the loss of visual functions mentioned above. For example, the discomfort related to the glare is amplified by the phenomenon of light scattering in the eye caused by opacities (cataracts, for example) or photoreceptor loss such as Age-related Macular Degeneration (AMD) [2].

Fig. 2: Night driving: loss of contrast sensitivity, glare.

Fig. 3: Aging effect of contrast sensitivity.
 

LOOKING AHEAD

In today’s times of technological advancements, the retired, elderly population not only still feels young but also enjoys a much more active life than their predecessor. Having good sight, good vision is really the key to their continued productivity and overall well-being. This will enable them to keep on doing their regular activities and also stay independent.

In conclusion, it is not only crucial to detect pathological and physiological issues experienced by the senior population, but it is also very important to dedicate time to listen and understand their daily visual needs. Following a detailed and thorough discussion with seniors will help in providing necessary and effective solutions which will allow them to enjoy the benefits of good vision leading to a long, independent and comfortable life. 

References