Mon-ayyy I can see!

I’ve worn glasses ever since I was in second grade. Yes, I was unfortunately THAT Asian girl who wore her hair in a middle part, high ponytail every day and had blue plastic glasses. Ever since I got glasses, naturally, my vision has gotten worse and I currently stand at a -9.00 prescription for my contacts. As someone who has had bad vision for two-thirds of her life, I was particularly intrigued by our vision module during our “Arts on the Brain” class. We began to explore the world of sight and learned that many famous artists had some sort of visual impairment. Claude Monet, a French impressionist painter, had cataracts which are speculated to have aided him in trailblazing the Impressionist art style. Our class wrapped lab goggles in plastic wrap to mimic the effects of cataracts, and we were able to see the beautiful gardens in Giverny through Monet’s eyes. This led me to research more about the cognitive effects of having visual impairments, specifically cataracts, and what Monet’s cognitive state might have been like.

Left to Right: original photo, drawing, drawing with cataract glasses

First, what exactly are cataracts? A cataract is a clouding of the lens in the eye, which lies behind the iris and the pupil. Our lens is analogous to a camera lens, hence the name, and it refracts light rays to help focus on image on the retina. A clear lens lets us see a clear picture. The lens is made of water and protein that is arranged in a precise way to keep the lens clear and let light pass through it. However, as we age, some of the protein may clump together and start to cloud a small area of the lens. This is a cataract. Over time, the cataract may grow larger and cloud more of the lens, making it even harder to see (NEI, 2015). Usually, aging is the most commons cause for cataracts, but traumatic injuries, UV exposure, and certain medical problems can also lead to the development of cataracts (Boyd, 2018).

Normal eye vs. Eye with cataract

Monet was diagnosed with cataracts in both eyes in 1912 at the age of 72, which aligns with what we would expect for age-induced cataracts. Monet was very reluctant to go through cataract surgery, and in the end, he only had restorative surgery in one eye. His left eye, clouded by a dense yellow cataract, could not see violets and blues, but his right eye could see these colors clearly. This distortion in color perception and acuity had an impact on his work where tones became muddier and darker and forms became less distinct. Monet apparently complained that “colors no longer had the same intensity for me” and that “reds had begun to look muddy”, and that “my painting was getting more and more darkened” (Gruener, 2015). Monet was audibly upset about his impairment, but I wonder if his mood or cognitive state would have been improved if he had gotten the surgery in both of his eyes.

Monet’s paintings of water lilies are impacted (Left 1889 vs. Right 1915)

Some studies have been conducted that look at the impact of cataract surgery on cognitive function in an aging population. A study by Jefferis et al. looked at the effect of cataract surgery on cognition, mood, and visual hallucinations in older adults who had bilateral cataracts. Participants, who were all 75 years of age or older, were assessed pre and post-operatively. The investigators measured visual acuity through logMAR, Addenbrooke’s Cognitive Examination (ACE-R), the 15-item Geriatric Depression Scale (GDS-15), and the North East Visual Hallucinations Inventory (NEVHI) (Jefferis et al., 2015). ACE-R evaluated six cognitive domains: orientation, attention, memory, verbal fluency, language, and visuospatial ability (Mioshi et al., 2006). Small but significant benefits in cognitive scores were seen 1 year after surgery, but there was no statistically significant difference in mood or hallucinations.

A different study by Fukuoka et al. in 2016 found that cataract surgery could improve cognition, although there was insufficient evidence for a definite conclusion (Fukuoka et al., 2016). A follow-up study in 2018 found that cataract surgery may play a role in reducing the risk of developing mild cognitive impairments independently of visual acuity, but not for dementia (Miyata et al., 2018). A loss of vision can be associated with loss of cognition. It is interesting to see how when the sensory input of sight is disturbed, there are cognitive effects that occur. The relationship between vision and cognition have not been explored extensively, but there are specific visual disorders that have been shown to share common pathogenic pathways with Alzheimer’s disease (Rogers & Langa, 2010). Some speculate that individuals with visual impairment allocate more attention resources to processing sensory information, leaving fewer resources for cognitive tasks (Lindenberger & Baltes, 1994). Additionally, there is a common factor to vision and cognition and that is the degeneration of central nervous function (Christensen et al., 2001. These studies provide great insight into how Monet or even people like our grandparents might be affected by declining vision.

Cute elderly couple with glasses

Cataracts and cognitive impairment are both age-related diseases. Especially with how the proportion of older adults are increasing in the world, it is important to see how we can improve their quality of life as they get older. These studies allowed us to gain more insight into how vision or sight for older populations may have an additional benefit of cognitive improvement.

References

Boyd K (2018) What Are Cataracts? American Academy of Ophthalmology https://www.aao.org/eye-health/diseases/what-are-cataracts

Fukuoka H, Sutu C, & Afshari NA (2016) The impact of cataract surgery on cognitive function in an aging population. Current Opinion in Ophthalmology 27:3-8

Gruener A (2015) The effect of cataracts and cataract surgery on Claude Monet. British Journal of General Practice 65:254-255

Jefferis JM, Clarke MP, & Taylor JP (2015) Effect of cataract surgery on cognition, mood, and visual hallucinations in older adults. J Cataract Refract Surg 41:1241-1247

Lindenberger U, Baltes PB. Sensory functioning and intelligence in old age: a strong connection. Psychol Aging 1994; 9:339–355

Miyata K, Yoshikawa T, Morikawa M, Mine M, Okamoto N, Kurumatani N, Ogata N (2018) Effect of cataract surgery on cognitive function in elderly: Results of Fujiwara-kyo Eye Study. PLoS One 13

National Eye Institute (2015) About Cataracts. National Eye Institute https://nei.nih.gov/health/cataract/cataract_facts

Rogers MA & Langa KM (2010) Untreated poor vision: a contributing factor to late-life dementia. Am J Epidemiol 171:728-235

Tay T, Wang JJ, Kifley A, et al. Sensory and cognitive association in older persons: findings from an older Australian population. Gerontology 2006; 52:386–394

Pictures:

At Giverny: My own

Cataracts: https://nei.nih.gov/health/cataract/cataract_facts

Monet, Bridge over a Pond of Water Lilies (1889): https://www.metmuseum.org/art/collection/search/437127

Monet, Water Lilies (1915):

https://www.royalacademy.org.uk/exhibition/painting-modern-garden-monet-matisse

Old people with glasses: https://www.aoa.org/patients-and-public/good-vision-throughout-life/adult-vision-19-to-40-years-of-age/adult-vision-over-60-years-of-age