Relief for Human Suffering Foundation

Understanding Visual Impairment: A World of Shadows and Hope

Visual impairment, as defined by the World Health Organization (WHO), occurs when an eye condition affects the visual system, impacting one or more of its essential functions. These conditions affect millions, casting shadows over lives that could otherwise be vibrant and clear.
The degree of visual impairment is typically assessed through visual acuity tests, which measure the sharpness of sight by identifying numbers and letters at standardized distances. It’s important to note that individuals who have corrected their vision with glasses or contact lenses are not counted when estimating the number of people in need of eye care.
Visual impairments encompass a wide spectrum, ranging from mild to severe cases, and can be categorized as near or distance presenting. For a deeper understanding, refer to our references for comprehensive information2,3. 
The Many Faces of Visual Impairment
Globally, cataracts and uncorrected refractive errors stand as the leading causes of visual impairments.  

In addition to these prevalent causes, other conditions also contribute to the global challenge of visual impairment, including:2,3

  • Age-related macular degeneration
  • Glaucoma
  • Diabetic retinopathy
  • Corneal opacity
  • Trachoma
  • Pterygium
Among these other conditions, pterygium, characterized by the growth of pinkish, triangular tissue over the white part of the eye, is a silent threat often unnoticed in the shadows. It can cause discomfort, blurred vision, and, if left untreated, even blindness. This condition is particularly prevalent in regions with intense exposure to ultraviolet (UV) light, like sunny climates in developing countries, such as Africa where it’s prevalence has been estimated to be up to 53% worldwide and 39% in Africa (6)
A Global Challenge
The prevalence of visual impairments varies significantly across regions and income levels. Low to middle-income regions face the brunt of this challenge, with four times more people affected by distance visual impairment and eight times more experiencing bilateral blindness compared to high-income regions.1,2,3
Our Mission: Bridging the Gap
At Relief for Human Suffering Foundation, we are passionately dedicated to reducing this disparity. We believe that everyone in need of eye care should have equitable access to it, regardless of their geographical location or socioeconomic status. With your support, we can transform this belief into a tangible reality, one person at a time.
Focused on the Leading Causes
Currently, our organization focuses on addressing the leading causes of visual impairments worldwide: cataracts, uncorrected refractive errors, and conditions like pterygium. By restoring sight and providing essential eye care services, we are working tirelessly to brighten the lives of those affected by these conditions. Your contribution can be the beacon of hope that helps us make a profound difference in the world of visual impairment.1


  1. Burton, M. J., Ramke, J., Marques, A. P., Bourne, R. R. A., Congdon, N., Jones, I., Ah Tong, B. A. M., Arunga, S., Bachani, D., Bascaran, C., Bastawrous, A., Blanchet, K., Braithwaite, T., Buchan, J. C., Cairns, J., Cama, A., Chagunda, M., Chuluunkhuu, C., Cooper, A., … Faal, H. B. (2021). The Lancet Global Health Commission on Global Eye Health: Vision beyond 2020. The Lancet Global Health Commission, 9(4), e489–e551. doi:10.1016/S2214-109X(20)30488-5
  2. Who Health Organization. (2021). Blindness and vision impairment.
  3. World Health Organization. (2019). World report on vision. 
  4. *, Oct 2015
  5. **World Health Organization
  6. Kassie Alemayehu, Yezinash Addis et al, Prevalence and Associated Factors of Pterygium Among Adults Living in Kolla Diba Town, Northwest Ethiopia