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The power of tears

Did you know that your tears provide 70% of your eyes focusing power?


It’s amazing but true

Your tears literally allow you to see by providing between 60 and 70% of your eyes focusing power. That’s why when your eyes dry out your vision can become blurry, it is also why when we squint or squeeze our eyelids closed our vision can temporarily be restored – we are simply topping up our natural tears.

Get the most from your lenses

This applies to everyone but it can provide a particular challenge to those of us who need help getting 20/20 vision. If you do require visual correction through glasses or contact lenses you will no doubt have made a considerable investment in getting the right prescription for optimum vision quality. However, if you don’t look after your tear film you won’t be getting the full benefit. This is especially true if you have dry eyes too.

Tears are much more than just water

Your tears are a highly complex and dynamic layered structure of mucin, water and oils (plus lots of other good stuff such as oxygen and nutrients). With every blink your tears spread across your eye creating a smooth, clear surface perfect for focusing the light into your eye.

It’s a bit like disturbing a reflection in a clear pool, once the surface is no longer flat and even the image becomes disrupted. It is the same principle when your tear film dries out.

A dry eye can make matters far worse

A characteristic of dry eyes is an unstable tear film, this can be for a variety of reasons and will vary from person to person. You might experience blurred vision and visual fluctuations throughout the day but more likely towards the end of the day. A study into these effects showed that moderate to severe blurred vision was reported in almost 60% of dry eye patients compared with only about 10% in the study group without dry eye. To gain a better understanding of the reasons for your dry eye it is important to seek the advice of your eye care professional. Some opticians have a special interest in this condition and offer special dry eye consultations to get to the cause of the problem.

Use an eye drop to help keep your eyes moist

One simple answer is to make sure your eyes remain moist. This is not always as easy as it sounds with the impact of central heating, air conditioning and long periods of computer work (reading at screens slows our blink rate and means less tears are produced). So to help keep eyes moist and comfortable, and our vision sharp consider using an eye drop or artificial tear such as HydraMed. A scientific study comparing the vision of people with dry eyes before and after using eye drops showed a statistically significant improvement in both near and distance vision after use.

The message is clear

Keep your peepers moist and your vision sharp. Experience the difference yourself with HydraMed from the Dry Eye Zone.

If you do find your eyes feeling dry or sensitive or you notice your vision losing acuity then ask the advice of your eye care professional.


Dr Jerry Robben. Vision care includes dry eye care. Optometry Times online. January 3, 2023.

The National Eye Institute.

Nilforoushan MR, Latkany RA, Speaker MG. Effect of artificial tears on visual acuity. Am J Ophthalmol. 2005 Nov;140(5):830-5. doi: 10.1016/j.ajo.2005.05.001. PMID: 16310460.

Vandermeer G, Chamy Y, Pisella PJ. Comparison of objective optical quality measured by double-pass aberrometry in patients with moderate dry eye: Normal saline vs. artificial tears: A pilot study]. J Fr Ophtalmol. 2018 Mar;41(3):238-245. French. doi: 10.1016/j.jfo.2017.05.025. Epub 2018 Mar 21. PMID: 29573863.

Wei, Z., Su, Y., Su, G. et al. Effect of artificial tears on dynamic optical quality in patients with dry eye disease. BMC Ophthalmol 22, 64 (2022).

Szczotka-Flynn LB, Maguire MG, Ying GS, Lin MC, Bunya VY, Dana R, Asbell PA; Dry Eye Assessment and Management (DREAM) Study Research Group. Impact of Dry Eye on Visual Acuity and Contrast Sensitivity: Dry Eye Assessment and Management Study. Optom Vis Sci. 2019 Jun;96(6):387-396.



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