Cataracts are the most common cause of blindness worldwide yet it is a treatable condition. Despite having a cost-effective and curative treatment available that dramatically improves the lives of the patient. See how here. Most of the people who need cataract surgery do not receive it. Broadly the barriers to receiving cataract surgery can be thought of as follows (ABCDEF):

Awareness
Despite treatment being available, blind patients and their carers are not aware treatment exists In many cultures, blindness is an accepted consequence of old age Bad service
In places where the service is not to a high standard, for example long waiting lists or poor outcomes of surgery, patients are unlikely to accept treatment Cost
The cost of delivering cataract surgery has been significantly reduced, however this may still be too much for some individuals The cost to the patient includes indirect costs (travel, time away from home) Distance
The further the health facility is from the patient, the less likely they are to attend Escort
If nobody is able to accompany a blind patient to the hospital they are unlikely to be able to make their own way there Fear
Various cultural stories around hospitals, eye surgery or blindness lead to people being too afraid to accept treatment Language for surgery in many cultures does not exist and term interchangeable with “butcher”, “split” or “cut” the eye are used and put off the prospective patient
More information on cataract surgery and preventing blindness in low-income countries is available from: The International Centre for Eye Health, The Community Eye Health Journal, The International Agency for the Prevention of Blindness, Peek Vision (mobile technology for eye health).

For more on eyes, watch and learn from these TED-Ed lessons:

A journey through the human eye
Could a blind eye regenerate?
The evolution of the human eye
What are those floaty things in your eye?