Prescription glasses, contact lenses or cataract surgery? The eclipse rules are the same

Yes, you can watch the eclipse of 2 August 2027 in prescription glasses, with contact lenses or after cataract surgery, and the rules are the same as for everyone else. Eclipse glasses go over your normal glasses, contact lenses make no difference, and the lens implanted during cataract surgery is not a solar filter. Keep an EN ISO 12312-2 filter on through every partial phase and take it off only during totality: in Tarifa, at the southern tip of mainland Spain, from 10:45:11 to 10:49:38; in Málaga, from 10:48:08 to 10:49:51 (Spanish time, CEST, UTC+2).

If you wear prescription glasses

Keep them on. The American Astronomical Society (AAS) puts it plainly: if you normally wear glasses, leave them on and put your eclipse glasses over them, or hold a handheld viewer in front of them. The Trío de Eclipses website, the official eclipse site of Spain’s Ministry of Science, adds a practical detail: hold them with both hands so they don’t move. If the person in glasses is a child, an adult should keep an eye on them and hold the eclipse glasses in place if needed.

Swapping the filter for prescription sunglasses, or for photochromic lenses that darken by themselves in sunlight, won’t do. They are still sunglasses, and the AAS is clear about those: however dark they are, they are not safe for looking at the Sun. The standard for looking at the Sun is EN ISO 12312-2; if a pair only mentions ISO 12312-1, the standard for ordinary sunglasses, it is not suitable. To check yours, see our guide to certified eclipse glasses.

Try both pairs on together before the day. In the path of totality the Sun will be high, about 37-41° above the horizon towards the east, so you’ll be looking up for quite a while, and it’s worth knowing in advance that the cardboard glasses won’t slip off.

If you wear contact lenses

Nothing changes. The Trío website sums it up in one line: with contact lenses, eclipse glasses are worn “in the usual way”.

It doesn’t matter either whether your lenses block ultraviolet. According to the eye-safety report that optometrist Ralph Chou wrote for the AAS, the danger when looking at the Sun during an eclipse is retinal burns caused by intense visible light, and those injuries don’t hurt. A contact lens isn’t made to remove that light.

If you’ve had cataract surgery

Cataract surgery replaces the eye’s natural lens with an intraocular lens so you can see sharply again. That lens lets visible light through, which is exactly the light that causes harm when you look at the Sun, so it gives you no protection: you need the same EN ISO 12312-2 glasses as everyone else.

Chou’s report also answers the other question that usually comes up, about ultraviolet. It is only a concern in an eye whose natural lens has been removed without any replacement that blocks it (a spectacle lens, a contact lens or an implant). And that same eye, looking through a proper solar filter, runs no extra risk.

If your operation was recent or you have another retinal condition, ask your ophthalmologist before the day. The American Academy of Ophthalmology warns that looking at the Sun without proper protection, even briefly, can damage the retina for good. The condition is called solar retinopathy.

Totality is the only break

For everyone, the filter comes off when the Moon covers the Sun completely and goes back on as soon as the first flash of sunlight appears. The IGN (Spain’s National Geographic Institute, which publishes the official eclipse times) asks people not to remove their glasses “until they are sure the Sun is completely covered” and to stop looking “before it ends”. Every town in the path has two times for each contact, ours and the IGN’s, and the safe choice is to take your glasses off at the later one and put them back on at the earlier one:

All times are mainland Spanish time, which is also the time in Ceuta and Melilla, Spain’s two cities on the North African coast. You’ll find more towns, and the signs that announce each contact, in when to take off your eclipse glasses during totality. Outside the path (Seville, Granada, Almería, Madrid) there isn’t a single second without a filter.

Before the day

Hold the filter up to the light before you use it: if it is scratched, has holes or is coming loose, throw it away, as the AAS and the Trío website advise. Put the glasses on before you look up and take them off after you look away, never while you are looking at the Sun.

On Order your glasses you can ask for ours: cardboard, with the EN ISO 12312-2 certificate, along with the phone filter and packs for groups. We reply with the price and the delivery time. The same form also lets you ask about the plastic version.

Sources: AAS — How to View a Solar Eclipse Safely (eclipse glasses over prescription glasses or a viewer held in front of them; sunglasses are not safe however dark they are; filter off only in totality; damaged filters go in the bin); Trío de Eclipses, official website of Spain’s Ministry of Science — Salud visual (in Spanish: over prescription glasses and held with both hands; children in glasses, with an adult; contact lenses “in the usual way”; ISO 12312-1 versus EN ISO 12312-2); B. Ralph Chou — Solar Eclipse Eye Safety, technical report published by the AAS (the damage comes from intense visible light and doesn’t hurt; ultraviolet is only a concern in an eye with no natural lens and no lens to block it, and with a proper filter there is no extra risk); American Academy of Ophthalmology — Solar Eclipse Eye Safety (solar retinopathy; protection comes off only during totality); IGN — Qué se ve en un eclipse total (in Spanish: totality as the only phase without glasses, and caution as it begins and ends); contact times and the Sun’s altitude: eclipseando data (skyfield engine + DE440s) and IGN times.