Blindness & Common Visual Impairment – 2020 Updated

Updated on - Written by
Medically reviewed by Victor Nguyen, PharmD.

Ocular Melanoma

The field of eye care is evolving constantly with new technologies and developments. More often, there seems to be a new test or instrument to improve the vision of visually-impaired patients. From eye tests to surgical procedures, more procedures are coming out of the picture to cure visual impairment.

While new technology can be often exciting, yet its downside remains to be its cost. Costs for new technologies and procedures can be high, adding to the financial burdens of patients. Besides, the newest vision treatment and/or the most expensive one does not automatically guarantee the betterment of your condition nor it is necessarily the best suited for you. Nonetheless, knowing your options is amazing.

If you’re experiencing a chronic eye problem, then you can simply contact your doctor and consult about any of the new vision treatments if you are interested

A potential new visual treatment for the rare eye condition called thyroid eye disease has been found. A study published in  the New England Journal of Medicine[1] showed patients who were administered with teprotumumab showed some positive impacts brought by the medication, such as  an improvement in their  vision, quality of life, and appearance.

Based on the study, the subject patients were able to receive the drug intravenously once per week for three weeks during the 21-week course. This phase 3 study contributed to the approval of the drug by the US Food and Drug Administration (FDA). The brand name for the drug is Tepezza, or teprotumumab as the generic name.

So how does teprotumumab work? Simply put, since it’s a human monoclonal antibody which can block inflammatory autoimmune pathophysiology that is involved with thyroid eye disease.

As for other developments in vision research, it’s time that we discuss the other research. Let’s find out about them below.

What is Visual Impairment?

visual impairment

Visual impairment describe a state of one’s eyes wherein they cannot be rectified to the “normal level”. It is, therefore, the functional limitation of one’s eyes or visual system. In some cases, it’s also interchanged with the term “vision loss”, pertaining to the loss of eye vision.

Basically, the condition of visual impairment refers to the decreased ability of one’s eyes to see to a certain degree, which is caused by some factors that cannot be easily corrected by typical means like the use of eyeglasses. Meanwhile, below is a run-down of the usual occurrences that can happen to you if you are visually-impaired.

Some possible manifestations of visual impairment include:

  • Discomfort when looking at light or photophobia.
  • The inability to view things clearly or the loss of visual acuity.
  • The inability to see a certain area as big as the healthy individual does without having to move one’s eyes or turning one’s head (loss of visual field).
  • The case of double vision or diplopia.
  • The distortion of images or visual distortion.
  • Difficulties with visual perception

80 percent of visual impairment cases[2] are estimated by the World Health Organization (WHO) to be either curable or preventable with proper care and treatment. Leading causes of vision impairments glaucoma, diabetic retinopathy, cataracts, trachoma infections, and refractive defects. Dealing with these vision impairment cases can involve the use of a variety of therapeutic techniques, such as vision therapy, environmental adjustments, and assistive devices.

Causes of Visual Impairments

We can get a visual impairment because of various factors. Neurological factors[3] can lead to functional vision impairment. Lifestyle[4] and light exposure can also affect the progression of vision impairment.

It is also worth considering the underlying illnesses[5] which may possibly lead to visual impairment. These include age-related macular degeneration, elevated eye pressure, and diabetic retinopathy, among others.

Characteristics of Visual Impairment

Individuals with vision problems that are non-correctable might result in visual impairments. Dependent on how severe a condition can get, certain characteristics may differ from one person to another.

Of course, loss of sight may be due to various medical conditions. Some of these causes that are not previously mentioned are cortical visual impairment, infection[6], and trauma[7]. Many conditions can impact sight with each condition having its own distinctive clinical features and characteristics.

Aside from the usual visual field problem and visual acuity problem, other vision problems can also affect the visual functioning of any person who has a visual impairment.

Some people can also become sensitive to light or glare and can have issues with how certain colors contrast with one another. Other people may also have blind spots in their visual fields. \Other factors like environment, lighting, emotional[8] status, and fatigue can affect an individual’s visual functioning.

Below are also some of the characteristics you would notice of a person, especially a child who has a visual impairment:

Physical signs

Eyes with irregular movement of fluttering may be a sign.. Having crossed eyes or issues with focusing are other cues that may indicate visual impairment in children.


Children who have vision problems may have a shortened attention[9] span. Squinting and blinking are some symptoms of visual impairment which may be noticed when children watch television or read. Children may also react to bright light due to sensitivity. Additionally, they can even hold books very closely or sit close to an object they want to look at.

Lack of coordination

Observe children who usually fall down or run into certain objects, or if they are have general coordination issues. When someone has a visual impairment, they may have difficulty realizing how far objects really are. They often have the inability to point out spatial positions[10] and consequently misjudge certain distances.

Types of Visual Impairment

There are two categories of visual impairments and these are:

  • Blind and partial blindness
  • Color blindness

Blind and Partial Blindness

Blindness or visual impairment can have many forms and can come in different degrees. Some people who have these conditions can utilize their considerable residual vision (remaining sight) in order to complete their daily tasks without depending on certain alternative methods.

However, those with significantly low acuity can benefit from specific training conducted by low-vision rehabilitation professionals[11] who are knowledgeable and trained enough in the technical aid provision. When you opt for this, you will be provided with advice on lighting and contrast so you can maximize your remaining sight. Furthermore, these low-vision rehabilitation professionals also have the right access to non-visual aids that they can recommend to you with instructions on how to use them.

On the other hand, people whose sight is worsening and whose prognosis of potential blindness is quite clear are most likely at risk of suicide[12]. This certain subpopulation who would have a high need for supportive services. Such interventions should perform at the onset of the condition or at the early stage of the diagnosis.

Here are the common causes of visual impairment under this category:

  • Uncorrected refractive errors
  • Cataracts
  • Glaucoma
  • Corneal clouding
  • Age-related macular degeneration
  • Diabetic retinopathy
  • Childhood blindness
  • Infections
  • Prematurity
  • Stroke
  • Trauma

This type of visual loss may also occur with other conditions, such as intellectual disability, cerebral palsy[13], hearing impairments, autism spectrum disorders[14], and epilepsy[15].

Additionally, some of the ways to assess an individual’s eye condition are through visual acuity. Visual acuity is the ability to discern the shapes and details of objects that you see. Visual acuity is often assessed through the use of an eye exam wherein an individual is tasked to see particular letters in large print and small print.

Color Blindness

visual impairment

When it comes to color blindness, there are various causes of such conditions. For most people who have deficient color vision, the common cause may be hereditary. Other people also experience color blindness due to other diseases like multiple sclerosis and diabetes[16]. Some people have also acquired it over time due to certain medications and disorders associated with the aging process.

What happens if you have color blindness? The majority of people with color blindness can clearly see things, but they may not see green, red, or blue. There are various types of color blindness with some rare cases like the inability to see any color.

The most common type of color blindness is red/green blindness, which is what most color blind people experience.

However, it’s worth mentioning that this color blindness[17] does not occur as a simple mix up of green and red when it comes to the individual who suffers from it. Instead, what appears to the eyes of the individual is the mix up of all colors that have hints of green and/or red as part of their entire color. For instance, a color blind person may confuse purple and blue because he/she cannot see the red element of purple.

How to Live With Visual Impairment

For many individuals who suffer from visual impairment and loss, such an experience can be psychologically stressful. However, there are already appropriate aids, tools, and services that can make an independent life possible despite such a condition.

Here are some of the ways and services that you can learn to help you adjust:

The use of aids and tools

Examples of aids and tools[18] are reading devices such as phones for the visually impaired and assistive technology for the visually impaired such as applications and software that can help blind or visually impaired read and use a computer. Service animals may also be helpful for navigating outside, although they require time to get used to using. Some valuable tools to facilitate communication are braille printing[19], audiobooks, and other computer applications that support speech recognition.

Re-organized daily life 

Some individuals who have vision loss have also learned to adjust by using white canes for walking[20]. Of course, like the above, you must learn how to use it over time so you would get accustomed to it. A more acceptable work environment would also be amazing for an individual with vision loss.

Socialization with other visually-impaired people

For some visually-impaired individuals, getting to share life with those who have the same experience would make you become understanding and accepting of your situation.

Furthermore, younger individuals like students who have vision impairment can seek support from special education schools.  These schools can conduct gatherings that aim to bridge connections among students who have a vision impairment. Local communities may also offer jobs for visually impaired people.

The New Eye Treatment

Precursor cells

For the very first time, Dr. Tiziano Barberi and Dr. Isabella Mengarelli of the Australian Institute of Regenerative Medicine of Monash University obtained purified lens epithelium. Lens epithelium is an embryonic tissue[21] which the eye lens grows. These precursor cells are further differentiated into lens cells, providing an opportunity in the laboratory for testing new treatments for human cells.  

With the help of activated fluorescence [22] cell sorting or also known as FACS, professor BarBeri and his companions were able to know the exact combination of protein signals applied to lens epithelium that allowed them to separate such cells from the remainder of the original tissue.

Most of these protein markers are common to more than one type of cell, which makes it difficult to determine the precise combination of these markers unique for the desired cells. Furthermore, these precursor cells further differentiate into lens cells, providing an opportunity in the laboratory for testing new treatments for human cells. 

Sooner or later, this research will enable us to treat vision impairment due to congenital cataracts or serious eye damage from lens replacement surgeries. Hopefully, this research will bring us a chance to grow parts of the human eye in the laboratory and are developing a treatment for congenital impairment in vision caused by lens damage.


While the ways on how to adjust to life with impairment and blindness are helpful, we would still continue to appreciate the new findings and developments on eye research. Advancements in technology and additional discoveries for this cause would certainly bring hope for individuals who still look forward to the day that they would gain the ability to see again.

+ 22 sources

Health Canal avoids using tertiary references. We have strict sourcing guidelines and rely on peer-reviewed studies, academic researches from medical associations and institutions. To ensure the accuracy of articles in Health Canal, you can read more about the editorial process here

  1. Raymond S. Douglas, George J. Kahaly, Amy Patel, Saba Sile, Elizabeth H.Z. Thompson, Renee Perdok, James C. Fleming, Brian T. Fowler, Claudio Marcocci, Michele Marinò, M.D., Alessandro Antonelli, Roger Dailey. (2020). Teprotumumab for the Treatment of Active Thyroid Eye Disease. Available from:
  2. World Health Organization (WHO). (2020). Visual impairment and blindness. Available from:
  3. Lotfi B. Merabet, D. Luisa Mayer, Corinna M. Bauer, Darick Wright, & Barry S. Kran. (2018). Disentangling How the Brain is “Wired” in Cortical/Cerebral Visual Impairment (CVI). Available from:
  4. M A Contín,  M Benedetto, M L Quinteros-Quintana & M E Guido. (2016). Light pollution: the possible consequences of excessive illumination on retina. Available from:
  5. Centers for Disease Control and Prevention (CDC). (2020). Common Eye Disorders and Diseases. Available from:
  6. Stephanie Watson, Maria Cabrera-Aguas, Pauline Khoo. (2020). Common eye infections. Available from:
  7. Edward J. Atkins, Nancy J. Newman & Valérie Biousse. (2010). Post-Traumatic Visual Loss. Available from:
  8. Jonathan R. Zadra & Gerald L. Clore. (2012). Emotion and Perception: The Role of Affective Information. Available from:
  9. Valerie Tadić, Linda Pring, Naomi Dale. (2009). Attentional processes in young children with congenital visual impairment. Available from:
  10. Giulia Cappagli & Monica Gori. (2019). The Role of Vision on Spatial Competence. Available from:
  11. David Turbert & Dan Gudgel. (2020). Low Vision Rehabilitation Teams and Services. Available from:
  12. DiegoDe Leo, Portia A.Hickey, GaiaMeneghel, Christopher H.Cantor. (1999). Blindness, Fear of Sight Loss, and Suicide. Available from:
  13. Gina Jansheski. (2020). Cerebral Palsy and Vision Impairment. Available from:
  14. Maggie Butchart, Joseph J. Long, Michael Brown, Anne McMillan, Janice Bain, Thanos Karatzias. (2009). Autism and Visual Impairment: a Review of Literature. Available from:
  15. Maxwell Lee. (2020). Ophthalmologic Manifestations of Epilepsy. Available from:
  16. National Eyes Institute. (2009). Colour Blindness. Available from:
  17. National Eyes Institute. (2009). Types Of Colour Blindness. Available from:
  18. Wafa Elmannai & Khaled Elleithy. (2017). Sensor-Based Assistive Devices for Visually-Impaired People: Current Status, Challenges, and Future Directions. Available from:
  19. American Foundation For The Blind. (2020). Braille Printers. Available from:
  20. Izaz Khan, Shah Khusro & Irfan Ullah. (2018). Technology-assisted white cane: evaluation and future directions. Available from:
  21. Isabella Mengarelli & Tiziano Barberi. (2013). Derivation of Multiple Cranial Tissues and Isolation of Lens Epithelium‐Like Cells From Human Embryonic Stem Cells. Available from:
  22. Boston’s Children Hospital. (2020). About Stem Cells. Available from:


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