A partial solar eclipse will be visible in Croatia on the evening of August 12. Experts warn of the key dangers of viewing it without proper protection and share tips for safely observing this spectacle.
Astronomy enthusiasts in Croatia and Germany will have the opportunity to observe a partial solar eclipse this evening. However, experts warn that this "true astronomical event," as Catherine Fischer from the European Space Agency (ESA) calls it, carries serious risks to vision if safety measures are not followed. Retinal damage can occur almost instantly, and the insidious part is that pain is not felt immediately. According to data from Germany, the eclipse began in most Croatian cities around 7:25 PM, and it will be most pronounced in the western parts of the country – from Poreč, nearly 90 percent of the Sun's disk will be obscured, from Rijeka about 85 percent, while in Split, the Moon will cover just over half of the Sun's disk.
Daniela Weiskopf, head of the optical radiation department at the Federal Office for Radiation Protection, highlights a particular danger of this eclipse. Since it occurs at dusk, the Sun is less dazzling, which leads to the absence of a key bodily defense. "This eliminates the natural human protective reflex," Weiskopf explained. An additional problem is that the pupil is more dilated at dusk, allowing more harmful radiation to reach the retina. Although the Moon covers a large part of the Sun's disk, the remaining radiation can still seriously damage the eye, experts warn.
Catherine Fischer, who at ESA is involved in planning solar observations with the Solar Orbiter spacecraft, emphasizes how quickly damage can occur. "It can happen very, very quickly," she warns. The retina has no pain receptors, so the body does not send a warning signal, and potential damage only becomes apparent several hours later. Symptoms include permanent dark spots in the visual field, blurred vision, or distortion of straight lines.
For safe viewing, special eclipse glasses with a certified filter are required. These have protective films that allow only about 0.001 percent of sunlight through. Welding glasses or ordinary films are not suitable. In Germany, they are already sold out in many places, with prices starting at 99 cents.
Weiskopf advises paying attention to several key criteria when purchasing. The glasses must completely cover the eyes, be marked as suitable for direct viewing of the Sun, and bear the CE mark. They should also meet the standard DIN EN ISO 12312-2:2015. The protective film must not have scratches or cracks, and old glasses from 1999 should be replaced with new ones. Sunglasses, films, and protective welding glasses are not adequate substitutes.
In addition to eyes, danger also threatens electronic devices. For photographing the eclipse with a smartphone or camera, a suitable filter is mandatory to protect the highly sensitive camera chip from solar radiation. Daniela Weiskopf emphasizes that a filter is essential for capturing a usable photo. The same rule applies to telescopes and lenses, which further focus the Sun's rays and must not be used for direct viewing without protection.
Those who cannot obtain protective glasses can make a simple pinhole camera from cardboard and tracing paper, which allows safe indirect viewing, especially suitable for children. For viewing this evening, August 12, you need to find a location with an unobstructed view of the horizon facing northwest. The Moon will move in front of the Sun shortly after 7 PM, when the Sun will already be quite low in the sky. The uniqueness of this event lies in the fact that it takes place very low above the horizon, so those with an open view to the west will be able to see the Sun setting while the Moon still partially covers it, which could create particularly striking scenes.
While the total eclipse will be visible along a line stretching from the Arctic Ocean, across Greenland, Iceland, and the Atlantic Ocean, to Spain and a small part of Portugal, Croatia and Germany will see its partial version. The total phase of this great astronomical event is visible in the area through which the path of totality passes, including Iceland and parts of Spain.
If accidental direct viewing of the eclipse without protection occurs, caution is needed. Since the retina does not feel pain, damage cannot be immediately recognized. If several hours later you notice symptoms such as permanent dark spots in your visual field, blurred vision, or distorted lines, Weiskopf advises an urgent visit to an ophthalmologist or eye clinic.
