About Visual Impairment
Your vision is our mission.
We use our sensory organs to obtain information from around us. With them we can move around without bumping into obstacles, listen to ourselves and others and carry on conversations, feel the temperature and shape of objects to enable us to make responses required for safety. We live and carry on activities with the help of our sensory organs.
While we use sensory organs, it is said the majority of the information from the surrounding environment is provided through the eyes. For this reason, impairment of vision can significantly affect daily life and activities.
We use these senses to engage in daily activities and avoid physical danger efficiently.
Visual Impairment and Current Challenges
Visual impairment is a condition in which a person has constant problems on seeing properly to a great degree. There are many different conditions that cause visual difficulties.
Difficulty in vision are wide‒ranging, and symptoms include restricted visual field and peripheral vision loss, blurred vision, ability to focus on far away objects but inability to read small letters in front of you. How one sees or how one finds difficulty in seeing depends mainly on which cell tissues in the eyes and brain that structure the human visual system have been damaged and to what degree.
This difficulty seeing may progress to the inability to see much to blindness depending on the cause and progress of the disease. However, thanks to research progress, there are diseases that can now be prevented, that can be cured to a certain degree or stopped from progressing further.
The chart below shows the causes of blindness around the world. Cataracts are ranked No.1. These are caused by the aging of the crystalline lens and anyone can be affected by this disease as they age. If cataracts are left untreated for an extended period, they may become severe and finally lead to blindness.
Today, however, there is surgery that replaces crystalline lenses affected by cataracts with IOLs (artificial lenses), making this disease treatable for almost complete recovery. The treatment is already common in countries such as the USA, Europe and Japan. This surgical procedure is spreading to other regions and nations throughout the world as well. It is hoped that blindness from cataracts can be prevented worldwide in the near future.
Blindness in the world
On the other hand, there are diseases for which no effective treatment has yet been established, disease that severely affect vision.
The chart below is the result of a survey conducted twice in Japan employing the same method to investigate the causes of severe visual impairment, including blindness. You can see that the causes of visual impairment have changed significantly over the years. For example, visual impairment from cataracts has dropped significantly; however, the percentage of glaucoma and macular degeneration, which are related to the tissue at the back of the eyes, such as the retina and optic nerve, has increased.
Visual impairments in Japan
Comparison of two surveys (2001–2004 and 1988)
Hisayama Study conducted in Kyushu looked into the prevalence of age‒related macular degeneration. The results showed that age‒related macular degeneration, which has been more common in the USA and Europe, is now increasing in Japan.
Age‒related macular degeneration: prevalence rate among 50 years old and above
Hisayama Study result
Having said the above, medical technology has succeeded in preventing certain eye diseases from becoming severe, while there are others for which the needs for treatment have not been sufficiently met.
Since its foundation, NIDEK has been cooperating with doctors and researchers in the development of new medical technology through our development of medical devices. Today, our challenge is to develop the visual prostheses for retinal disease patients with no effective treatment available.