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Your Eye Health: Which Lenses to Choose?

How Does The Human Eye Work?

The human eye is a photoreceptor organ, whose function, already implicit, consists of receiving the luminous rays coming from the objects present in the external world and transforming them into electrical impulses that are conducted to the nervous center of vision in the back of the brain.

The eye needs a certain period of adaptation to pass from a luminous intensity corresponding to daylight, to lower intensities of light and vice versa. This period of adaptation is related to a very sensitive structure, which is in charge of capturing light: the Retina.

The movements of the eyeball to the right, left, up, down and sides are carried out by the six ocular muscles and are very precise. It has been estimated that the eyes can move to focus on at least one hundred thousand different points in the visual field.

The muscles of both eyes work simultaneously, so they also play the important role of converging their focus to one point so that the images of both coincide; when this convergence does not exist or is defective, double vision occurs.

Eye movement and image fusion also contribute to the visual estimation of size and distance.

From the optical point of view, the eye has an analogy with the dark room of a photographic machine. The two retinas are excited by stimuli from the environment and the optical images formed in it are inverted. Through a process that takes place in the brain, the sense of the perceived object is restored.

To reach the Retina, a beam of light must pass through the refracting means of the human eye, which are four:

The curved surface of the retina is very important, since it allows compensating the change of trajectory that a light beam suffers, when passing through media with such different diffraction indexes. Once inside the eye, the refraction indices of the crystalline lens, aqueous humor and vitreous humor, are so similar, that the light beam does not suffer much change, only the inversion we mentioned before.

Functioning of the Eye


The eye receives light stimuli from the environment. Light passes through the transparent media and lens of the eye and forms an inverted image on the retina. In the retina, specialized cells transform the image into nerve impulses. These reach the back of the brain through the optic nerve. The brain interprets the signals through a complex mechanism involving millions of neurons.

Pupil and iris

The iris is a circular diaphragm that regulates the amount of light entering the eye. It has a central hole of about 3 mm in diameter, the pupil. This one adapts to the intensity of the light. If the light is intense, the pupil contracts (miosis), if the light is scarce, the pupil dilates (mydriasis).

The constriction of the iris is involuntary and is controlled automatically by the parasympathetic nervous system, the dilation is also involuntary, but depends on the sympathetic nervous system.

Cornea and crystalline

The cornea is an ocular tissue that is found in the front part of our eyes, it is totally transparent and among its diverse functions is that of protecting the iris and the crystalline lens, the cornea besides protecting other ocular structures has the function of focusing together with the crystalline lens the images in our retina.

We can consider the cornea as the first of the lenses that conform the optical system of our eyes.

Due to this condition of first lens, the cornea has a great importance in our vision, a lack of transparency or a deformity in our cornea will cause a bad image in the retina.

As a consequence of the boom of the refractive surgery with laser in these last years important advances in the knowledge of the structure of the cornea have taken place, this weave is every time better known and as consequence the security and effectiveness of the surgical interventions is every day greater.

The crystalline lens is a biconvex and transparent lenticular body of the eye, whose functions are to maintain its own transparency, refract light, and provide accommodation.

It does not possess irrigation or innervation after fetal development, depending completely on the aqueous humor for its metabolic requirements and to carry out its waste excretion. The crystalline lens is located before the vitreous body, after the iris and is suspended in position by Zinn zonules, which are fibers that hold it to the ciliary body.


It is the process by which light from a distant object and a nearby object is focused on the retina.

The light rays that penetrate the eye must be focused exactly on the retina so that the image obtained is clear. This requires an adjustment that occurs in a very similar way both in the human eye and in the rest of the vertebrate animals. The process by which light rays from both near and distant objects are focused exactly on the retina is called accommodation. The mechanism of accommodation requires the contraction of the ciliary muscle that is attached to the lens by the suspensory ligament.

If the ciliary muscle contracts, the crystalline lens becomes more spherical and increases its refractive power, allowing it to focus light from near objects. When the ciliary muscle relaxes, the crystalline lens becomes less spherical and its refractive power decreases, allowing us to see distant objects clearly.


In the retina are the visual cells, so it can be compared to a photosensitive film. These cells are capable of capturing visible light which is only a small part of the electromagnetic spectrum, that is, between 400 nanometers of violet light and 750 nanometers of red light.

The light that strikes the retina triggers a series of chemical and electrical phenomena that eventually translate into nerve impulses that are sent to the brain by the optic nerve.

Cones and rods

The sensory cells of the retina react differently to light and colors. The rods are activated in the dark, and only allow black, white and different grays to be distinguished. The cones, on the other hand, work during the day and in bright environments, make color vision possible.

In the human eye there are three types of cones, sensitive to blue, red and green light respectively. Each of them absorbs the radiation of a certain portion of the spectrum because they have some pigments called opsins. Opsins are molecules that are formed by a protein and a vitamin A derivative. The erythropsin has greater sensitivity for long wavelengths of about 560 nm (red light), chloropsin for medium wavelengths of about 530 nm (green light) and finally the cyanopsin with greater sensitivity for small wavelengths of about 430 nm (blue light). Through the different intensities of the signals produced by the 3 types of cones, we can distinguish all the colors that form the spectrum of visible light.

The cones are concentrated in the center of the retina (macula), while the rods are more abundant on the periphery of the retina. Each cone is individually connected to the visual center of the brain, which in practice allows us to distinguish at a distance of 10 meters two luminous points separated by only one millimeter. Each human eye has 7 million cones and 125 million rods.

Ocular health

The community pharmacist, in his usual assistance work, resolves numerous consultations about ocular pathologies and informs patients about the use of ophthalmic medicines.

Every second Thursday of October, World Sight Day is celebrated with the aim of raising awareness about visual impairment and informing about options to maintain proper eye health. The community pharmacist, in his usual assistance work, attends to numerous consultations of patients about ocular pathologies. Among the most frequent are:

On the other hand, the pharmacist intervenes in the dispensation and pharmacotherapeutic follow-up of the ophthalmic treatments prescribed. Likewise, he informs the patients about the administration of the medicines through the eye:

Eye drops

Eye drops are sterile, aqueous or oily solutions or suspensions of one or more active ingredients, intended for instillation into the eye. As they are sterile liquids, eye drops are easily contaminated if handled incorrectly. Once opened, the eye drops have a shelf life of one month, so it is necessary to be especially careful or use single-dose. One of the first precautions we must take when administering an eyewash is to avoid contamination, so it is advisable to always wash your hands before handling these medicines. To facilitate the application of the eyewash, the appropriate thing to do is to lower the lower eyelid, depositing the drops in the cavity that is formed. It helps in the procedure to incline the head a little backwards and towards the side of the eye where the drops will be administered. To avoid contamination of the medicine, it is important that the tip of the applicator does not come into contact with any surface of the eye. When using an eyewash it is also essential to apply the exact number of drops prescribed, and then blink a couple of times to spread the drops over the entire eye surface. It is recommended that you subsequently close your eyes for a few minutes, to wipe away any excess liquid that may spill out. If you need to apply a second eyewash, it is better to wait a few minutes so that the first one can be properly absorbed. With all these precautions, we will achieve optimum conditions so that the medicine can fully develop the expected action.

Eye baths

Eye baths are sterile watery solutions, intended to wash or bathe the eye or to impregnate the bandages applied to the eye.

They are indicated in the treatment of infections, inflammatory processes or simply to remove contaminants or foreign bodies from the eye surface. They are also used in preparation prior to surgery. In general, very active drugs are not used in eye baths. They are usually antiseptic solutions or physiological serum.

Do not forget: Always ask your pharmacist. He will inform you about these and other related issues. And remember that pharmaceutical intervention is a high guarantee in the overall process of effectiveness and safety of drug treatments, as well as in health education.

Importance of visual health


Vision care is one of the most important aspects of your children’s health, as problems related to vision loss or disease can occur in both youth and adulthood and can increase over time.

The first exam, after birth is performed by the pediatrician, who will be the person responsible for verifying up to 6 months the visual health of your baby, then it should be done when the doctor considers it convenient the complete vision exam to rule out any type of advanced problem, this should be done before 3 years.

Then, with the growth and the results of the previous examinations you should take your child to an annual visual health exam, there they will rule out any type of complication. If your child presents any problem in the examinations during the first age you should take preventive measures against other diseases and ensure the care and improvement of their vision.

Any visual complications in the early years of development may increase over time and become a short or long term problem.

How do I take care of my eyes?

Whether you wear glasses or not, to keep your visual system in shape follow these tips:

Eating habits are very important to take care of our visual health. A healthy diet with the presence of vitamins (A, C, E…) and antioxidant elements has many benefits for eye health.

Eye hygiene is also very important. You should not touch or rub your eyes with your hands, as you could expose them to infections.

It is essential that you protect your eyes from the sun with approved sunglasses, which you can find in your trusted optician’s shop.
We must avoid unnecessary efforts on our sight. Not wearing the right optical correction forces our eye to make an extra effort which is harmful.

Sleeping little makes the eye not recover well from the aggressions of the day. During the night there is a regeneration of the epithelial cells that cover the anterior face of the eye.
It is very important to illuminate well the object that we are looking at (a book, a cell phone, the TV, etc) but without reflections and without the light falling directly on our eyes.

We must maintain an adequate distance from the objects we are looking at. The TV at least 2 meters and when we go to read or write try to be about 35-40 cms.

Tips to take care of the visual health of your eyes:



Some tips for the care of your eyes, very important for a good quality of life. Care, protection and correct maintenance of the eyes.


Vision checks are health insurance. They can uncover problems and help prevent diseases that can damage your vision or well-being. Quick, simple and painless, eye exams by an eye care professional protect your vision and your health.


Some eye diseases can be genetic. The most common inherited visual conditions are age-related macular degeneration (AMD), glaucoma and cataracts. Early detection is often key to proper management and treatment of these conditions, which is why it is so important to know your family’s health history.


A healthy diet provides you with the nutrients, vitamins and anti-oxidants needed to help protect your eyes from UV light damage and prevent certain eye problems. Exercise helps prevent overweight and high blood pressure, a condition that can damage vision. These two factors together contribute to the maintenance of a healthy body mass index (BMI) and prevent diabetes, a condition that causes vision loss in older people.


It is important to protect your eyes from the potentially harmful effects of overexposure to digital device screens. Adjusting screen brightness, resolution and contrast, taking regular breaks and avoiding glare can help prevent Computer Vision Syndrome (CPS).


UV rays can be as harmful to your eyes as they are to your skin (and we’re exposed to them every day). For daily protection, it is recommended that eyeglass wearers have a UV filter on their eyeglass lenses. The sun protection factor (E-SPF) for the eyes is a must for sunglasses, to block harmful rays and prevent disease.


Most eye injuries can be prevented by wearing the right protection. According to the American Academy of Optometry, half of all eye injuries occur during everyday activities, such as cooking, cleaning, gardening or DIY. Some sports and outdoor activities, such as biking, skiing or playing tennis, also increase the risk of eye injuries.


The hidden effects of the screens. Tips and solutions to protect your eye health from digital devices.


Smartphone, computer, tablet, TV: screens have become an accomplice of our life. But do you know that your excessive consultation can cause physical and mental disorders?


It is difficult to escape from the screens: school, work, leisure or even travel, we always have an eye on a screen. A good posture and some easy and quick gestures or exercises can be essential to live better every day.


Since screens are always associated with pleasure and knowledge, it is necessary to regulate and adapt their use. Discover our different solutions to avoid the potential risks associated with excessive exposure.



The eyes are complex organs, susceptible to environmental, age and genetic factors.

Strabismus occurs when a person’s eyes focus in different directions. This condition can lead to blurred vision, double vision, or lazy eye.

Cataract is a visual problem that occurs when the lens becomes opaque, making vision hazy. It is a very common disease in older people.

This is an abnormal sensitivity to light that can cause headaches and visual discomfort. Those who suffer from it experience significant discomfort even in moderately bright environments.

Those who suffer from color blindness may find it difficult (or even impossible) to see certain colors. There are different degrees and different types of color blindness.

Computer Vision Syndrome (CWS) is a term under which different eye and vision problems caused by looking at the screens of different electronic devices for long periods of time are grouped together.

The lazy eye is most common during childhood and is usually easy to treat. But, if left uncorrected, it can permanently affect vision.

Dry eye syndrome (keraconjunctivitis sicca) affects mainly the elderly. It is quite common and easy to treat.


There are many things you can do to protect your vision. Find out more about protective lens technology and the benefits of regular visits to your optician…


Some sports and outdoor activities can increase the risk of eye injury.

In addition to protecting your eyes, glasses help you see better by reducing, for example, glare from the sun when you ski or drive.

Polarized glasses are very useful for golfers, fishermen and tennis players. They are also recommended for swimmers.


About half of all eye injuries result from everyday tasks such as cooking, cleaning or gardening.

It is recommended that you wear safety glasses to protect your eyes from splinters and chips when doing DIY, when using power tools and lawn mowers. It is also important to protect your eyes when doing sports and when you are going to be exposed to the sun’s rays.


Some sports and outdoor activities can increase the risk of eye injury.

In addition to protecting your eyes, glasses help you see better by reducing, for example, glare from the sun when you ski or drive.

Polarized glasses are very useful for golfers, fishermen and tennis players. They are also recommended for swimmers.


Fast, simple and painless, eye exams are the most effective tool to protect your vision and health.


Find out how you can protect your vision from daily exposure to UV and blue-violet rays.


Nutrition and exercise benefit your eyesight and help you stay healthy.


Regular use of digital devices can damage your eyesight. It is important to protect your eyes.


Your genes can affect your vision and the likelihood of developing eye problems.



When selecting the lenses of your glasses, you need to consider different options, taking into account materials, properties, etc. Knowing something about the lenses will help you better understand your optician’s recommendations.


Billions of people in the world wear glasses. We encourage you to learn more about how their most important component – the lens – works.


Lens technology can improve the performance and appearance of your glasses. Find out how it protects you from the enemies of vision.

Custom Lenses

No two eyes are the same in the whole world. Thanks to customization, each lens is tailored to give you the best possible vision and comfort.

Photochromic lenses

Photochromic lenses remain clear indoors and dark in bright light conditions. Their qualities make it unnecessary to switch between eyeglasses and sunglasses.

Progressive lenses

Unlimited vision at any distance without having to change glasses.

High Index

Find out more about high-index lenses, which are thinner and flatter than standard lenses. Their qualities allow those with high prescriptions to wear very thin lenses.



Consult your eye doctor, he can help you select the one that is best for you.


Not all lenses are the same. Choosing the right lens is essential and should be your first priority when considering new eyewear.

Glare Resistance

The glare you get when driving at night or when you spend many hours in front of the computer screen can be very uncomfortable. That’s why there are lenses that reduce the effects of glare.

Scratch Resistance

Scratches can ruin your glasses. They can fog up, stain and make it hard to see through your lenses, so we’ve got some tips to keep your glasses safe and scratch-free.

Dust repellent lenses

Get better vision through your lenses by following these simple tips; they will help keep your glasses clean and dust free.

Stain Resistant

Dirty fingers or fingerprints, make-up, pollution… there are many causes that can cause your glasses to become stained and leave your vision blurred. Here are some tips to keep your glasses clean.

Choosing frames

There are many factors to consider when choosing a frame. We must find the perfect balance between style, comfort, budget and, most importantly, improved vision.

Understanding your prescription

Learn more about your optician’s prescription. What does it mean and how does it affect your new lenses?

Water Repellency

These easy steps will help you avoid water spots on your glasses.



Discover contact lenses

Many people wear contact lenses and glasses. Those who wear them often find them comfortable, practical and effective for therapeutic purposes.


Contact lenses are thin plastic lenses that are placed directly on the surface of the eye, usually to correct vision. They can also be used for cosmetic or therapeutic reasons.

There are two main types of contact lenses: soft and rigid gas permeable (RPG). Despite their name, both are gas permeable. This means that they allow oxygen to pass through them to reach the eye, maintaining the health of the cornea. Without an adequate supply of oxygen, the cornea can swell, causing vision problems. Your contact lens specialist will be able to explain which ones are a better fit for your vision and lifestyle.

Soft progressive or multifocal lenses have also been designed to help correct the effects of presbyopia, an age-related visual condition that causes blurred vision when focusing on close objects.