Birendra Mahat, B.Optom

Santosh Chhetri, B.Optom

M. Optom Student, Tilganga Institute of Ophthalmology, Nepal



Nepalese ophthalmic lens market is irrelevantly populated with the direct impact of economically giant neighbouring countries: India and China. In this line, the hoax marketing has brought about unclear doubts and unresolved issues in patient care.

Blue-blocking spectacle lenses, with varying degrees of short-wavelength light attenuation (ranging from 10% to 100%), are being marketed to the general population. In addition, both professionals in medical practice and salespersons at the optical outlets claim that these lenses alleviate eyestrain and discomfort during the electronic gadget’s use. It is deceptively claimed to improve sleep quality and probable protection from retinal photo toxicity. There is a debate whether these lenses really support any aforementioned statements. The low certainty of evidence has paved a smooth path for the business for many.

The Problem:

The present marketing swindle lies largely in the blue light glasses which go by different names – blue light blocking glasses, blue light filter glasses, blue blockers, or blue cut glasses. There is an unmatched resonating perception or views in the professional practice of eye care practitioners and the salesmanship of the optical salesperson (qualified, trained, or amateur).

Figure 1: Blue light (wavelength) in the electromagnetic spectrum
(Picture Courtesy: Gary Heiting, OD)

The Unchanged Fact:

Blue light is categorized into three sub-groups from high-energy to low-energy levels Violet light (~ 380- 415nm), Blue-Violet light (~ 415-455 nm) and Blue-Turquoise light (~ 455-500nm). The higher the energy levels, the more harmful are the effects. When any source produces light, different colours vibrate at different wavelengths wherein the high energy visible light (HEV) is the blue-violet light which resembles a part of the sun’s potentially damaging blue light. Through various results from research and meetings, there has been a significant change in the light source’s increased use of compact fluorescent lamps (CFL) and high-intensity light-emitting diodes (LED). To add, the backlit displays in smartphones and tablet computers use white-light LEDs. Hence, constant exposure causes increased free radical production and reduced cell viability 7 leading to retinal toxicity and risk of age-related macular degeneration. (1)

Blocking short wavelengths causes disturbances of colour perception, decreased scotopic sensitivity, and disruption of the timing of the circadian system. (2) Fundamentally, photosensitive retinal ganglion cells, which provide photic input to the central circadian clock in the suprachiasmatic nucleus, express melanopsin and have an absorption peak at approximately 480 nm in the blue part of the spectrum. (3)


The standard spectacles lenses provide protection against UV up to 380nm whereas adding a yellow chromophore can also further reduce or eliminate blue light transmission. A complete block of all the range of blue light wavelength is something which is undesired. Socio-economic factors, hobbies, and occupations like web designers, photographers, etc. are a few considerations in patient care. Moreover, modern days hi-tech has an in-built eye care function enabled. The natural outlook, as of normal eyes, from any coated lens should not alter the quality of view in terms of contrast and colour. The salesmanship acts should not overcome the ethical clinical practice in ophthalmic dispensing. Thus, there is a need for empathetic feeling, with the addressable to the key issues of the patient being a prime objective of any eye care professional. There is a high need for both experienced and trained optical dispensers. Righteous counselling plays a key role in worrying parents about their children’s protection of eyesight and vision.

Dr. Hunter Patch   Adams mentions – “You treat a disease, you win, you lose. You treat a person, I guarantee you, you will win, no matter what the outcome”



  1. Moon, J., Yun, J., Yoon, Y. D., Park, S. I., Seo, Y. J., Park, W. S., … & Kang, J. S. (2017). Blue light effect on retinal pigment epithelial cells by display devices. Integrative Biology9(5), 436-443.
  2. Cuthbertson, F. M., Peirson, S. N., Wulff, K., Foster, R. G., & Downes, S. M. (2009). Blue light–filtering intraocular lenses: Review of potential benefits and side effects. Journal of Cataract & Refractive Surgery35(7), 1281-1297.
  3. Do, M. T. H., & Yau, K. W. (2010). Intrinsically photosensitive retinal ganglion cells. Physiological reviews.