Solar eclipse: here’s how it can damage your eyes and how to protect them during the two minutes of ‘darkness’

A solar eclipse is a spectacle that hasn’t been seen in Europe for at least 30 years, but curiosity must not be allowed to put your eye health at risk. Viewing an eclipse without filters can cause damage to the retina – which may even be permanent – or even lead to eclipse-induced macular degeneration. That is why you must wear special glasses, certified for viewing the eclipse itself, which are readily available on the market. Here are the risks and how you can protect yourself during this eclipse, which is expected to last just over two minutes.

In recent days, the Ministry of Health has reiterated that, according to the guidance issued by international health organisations (WHO, CDC, Prevent Blindness), a solar eclipse poses no direct risk to human health (such as effects on pregnancy or nutrition), with the sole exception of permanent damage to the eyes caused by looking directly at the sun, even for a short time. This is why, before observing the eclipse, it is essential to wear specific eye protection – sunglasses are not sufficient – which must be worn at all times.

The main risk is damage to your eyesight: looking directly at the sun or a solar eclipse – even for a short time – can cause permanent damage to the retina (solar retinopathy), without causing any immediate pain. The risk is increased in the case of repeated observations, even if brief. Damage may not become apparent until hours or days later. For this reason – as the Ministry of Health reiterates – there is only one safe means of protection for direct observation: looking at the sun whilst wearing special eclipse glasses (Eclipse Glasses) that are certified as complying with the ISO 12312-2 standard. Any other method must be avoided as it does not always guarantee safe protection: for example, sunglasses (even when worn one on top of the other), X-ray film, homemade filters, welder’s goggles, camera viewfinders or similar items are not sufficient. Children and young people are at greater risk, as their eyes are more vulnerable to damage, and because the fascination of the phenomenon may draw them towards looking directly at the Sun.

For them, viewing the eclipse should take place under the constant supervision of adults, who must ensure that children and young people wear eclipse glasses at all times. Older people, those with pre-existing eye conditions or those who have undergone certain eye surgeries may be among those at greatest risk. In any case, if you notice any vision problems, even mild ones, in the hours or days following the eclipse, it is important to seek an eye examination immediately.

According to Mario Sbordone, head of the Ophthalmology Department at Santa Maria delle Grazie Hospital in Pozzuoli: “The danger also stems from a false sense of security. When the sun’s disc is partially obscured by the moon, the light may appear less intense, but this does not mean that looking directly at the sun is safe. The radiation reaching the retina can still cause solar retinopathy, that is, photochemical and thermal damage to the retinal cells.” A particularly insidious aspect is that the retina has no pain receptors. “Anyone looking at the sun without protection may not feel anything immediately,” explains Sbordone, “and may only realise there is a problem in the hours that follow or even after a few days. Symptoms may include blurred vision, colour distortion, dark or bright spots in the centre of the visual field, image distortion or a reduction in visual acuity. In some cases, recovery may be only partial.” Hence the advice to avoid any makeshift solutions. “Ordinary sunglasses, even very dark ones, are not sufficient,” the expert emphasises. “You must not use tinted glass, photographic or X-ray film, CDs, homemade filters or other makeshift solutions that may appear protective but do not guarantee the necessary filtering of solar radiation. To view the eclipse directly, you must use only devices specifically designed for solar observation and compliant with the international standard ISO 12312-2.”