Sea, snow, high mountains… in summer our eyes are more exposed to the sun. The light that reaches and penetrates the human eye is divided into visible spectrum (between 380 nm and 780 nm) and non-visible spectrum (which includes ultraviolet rays and infrared rays). Ultraviolet (UV) rays are very harmful as they are absorbed by the cornea and lens of adult individuals, while blue light (between the visible spectrum and UV rays) penetrates the lens damaging the retina. Why is it important to protect summer eyes? How can we safely expose ourselves to the sun? What are the optimal characteristics of a pair of sunglasses? In this interview answers Dr. Francesco Loperfido, Head of the General Ophthalmology Service of the IRCCS San Raffaele Hospital, answers.
Dr. Loperfido, why is it important to protect our eyes during summertime?
In summer the eyes are exposed to excessive contact (direct or indirect) with UV rays. This exposure, more frequent to the sea, on the snow or in the high mountains, can determine an actinic conjunctivitis, painful keratitis and photophobia: it is therefore necessary to protect the eyes adequately.
In particular, attention must be paid to two categories:
- children, whose eyes are still in a phase of growth and development;
- elderly people, who have a less hydrated eye and are more prone to photophobia, to which are often added problems related to aging.
A general rule valid for all is to adapt the protection of our eyes in relation to your holiday place: the amount of UV rays is different depending on whether we are in the city, at the beach or in the mountains, and the quality of protection must therefore be different.
How can we protect our eyes?
In very high mountains, for example, you need to choose glasses with mirrored lenses that shield you from UV rays but also blue light that reaches the peaks, and that adapt efficiently to climatic changes. If we go to very windy places we might prefer a curved eyewear. At sea instead it is better to choose a polarized lens, which removes water reflections; an interview with the optician will allow customizing the glasses according to our needs.
It is also very important to identify the type of lens based on a possible visual defect: sometimes, green lenses can cause nausea in subjects with strong myopia, while brown lenses can cause nausea in very hypermetropic subjects. In old age photochromic or intelligent lenses, which change their color from completely transparent inside our homes to partially colored in cars (most of the UV rays are absorbed by the windshield of the car) can be very dark when they change we are outside.
Does a bright-eyed person have to pay more attention than those with dark eyes?
Yes; the light eyes must be protected more carefully because they have less pigment at the level of the iris and retina, two epithelia that contribute to defend our eyes.
How to choose the perfect sunglasses?
There is no “perfect eyewear”, but it is possible to identify some characteristics that make it optimal:
- high quality lenses, as poor lenses are impure and do not always manage to block harmful radiation;
- organic (unbreakable) lenses, more resistant and safer than a crystal lens (in the unfortunate event of an car accident, the airbag would not break the organic lenses);
- frame suitable to our face (not too big compared to eyeglasses) and to our possible visual defect. Especially for children, let’s make sure it is a good quality frame, purchased exclusively from verified sales channels, to avoid allergy phenomena due to poor materials or inadequate eye protection due to poor lenses.
What last recommendations you would give, especially to young people?
Few but important points:
- Don’t buy glasses with strange colors just because of fashion: they might be more aesthetically pleasing, but they don’t often protect our eyes adequately.
- Identify the type of lens you need, depending on where you are going on vacation (sea? Mountain? City?).
- Especially for those who practice sport, choose glasses alone that meet your true needs, to support you not only during the summer, but throughout the year.