Frequently Asked Questions (FAQ)
We have established this list of Frequently Asked Questions based on inquiries we receive and search volume on Google.
If you feel you have a question that has not been answered and should be listed, please feel free to contact us.
We will gladly consider your request
1. Frequently Asked Questions about Eclipse Glasses
We strongly recommend buying your solar eclipse glasses several weeks before any upcoming eclipse.
As the event approaches, demand rises exponentially, and many people try to place last-minute orders. This surge often causes shipping delays and logistical bottlenecks, preventing glasses from arriving on time.
Additionally, suppliers may run out of stock since inventory depletes quickly in the days leading up to the eclipse. Once this happens, finding certified glasses from trusted sources can become difficult—or even impossible.
To guarantee your safety and peace of mind, we recommend securing your glasses early and avoiding last-minute stress.
Preparing in advance ensures timely delivery and gives families with children the chance to practice safe eclipse viewing ahead of time.
Purchase your eclipse glasses only from trusted, well-known brands or authorised vendors.
Although the ISO 12312-2 logo is often printed on genuine products, the most reliable way to confirm authenticity is by checking the manufacturer’s certification test reports. Only a few reputable suppliers make these documents publicly available online.
Technically, no—if they are undamaged and have been stored properly.
If your glasses meet the ISO 12312-2 standard and the lenses have no scratches, holes, or visible damage, they can be reused indefinitely.
That said, we recommend caution. Over time, improper storage or use can cause micro-damage not visible to the naked eye. For this reason, many sources advise discarding glasses that are over 3 years old.
When in doubt, the safest option is to replace them.
To prolong the life of your eclipse glasses, follow these tips:
- Store them flat in their original packaging, a protective envelope, or a ziplock-style plastic bag.
- Keep them in a cool, dry place, away from direct sunlight and heat sources.
- Do not fold or crease them, as this can damage the solar filter.
💡 A surprisingly effective storage spot?
The fridge (inside a sealed bag), where temperature and humidity stay low.
We recommend not cleaning them unless absolutely necessary. If you notice dust or smudges:
- Use a dry, soft, lint-free cloth to gently clean the lenses.
- Never use water, solvents, or cleaning products.
- Keep the cardboard frame completely dry; moisture can warp it or loosen the lenses.
✅ Yes! Most eclipse glasses are designed to fit securely on both adults and children.
👀 However, children should always use them under adult supervision.
🧒 If you’ll be watching an eclipse with small children, practice indoors beforehand so they learn how to wear them correctly. (see 'How to Use Eclipse Glasses Safely?)
🔒 ISO 12312-2 certification alone does not prevent damage if the glasses are misused, damaged, or improperly worn.
👁️🗨️ It is the user’s responsibility to carefully follow safety instructions.
2. Frequently Asked Questions about Vendors
We only list vendors that sell established brands with a proven track record, have published ISO 12312-2 certification reports, or are recognised companies that existed before entering the eclipse-glasses market (for example, opticians).
We do not include vendors or websites that:
- Only publish affiliate links to other sites
- Do not provide verifiable company information
- Cannot produce lab reports supporting their ISO certification claims
- Do not ship within or to Spain
- Have no stock available
All vendors included in our comparison have been reviewed based on available certification data, company background, and customer reliability.
However, we are not an official certifying body and therefore recommend that buyers verify ISO 12312-2 documentation directly whenever possible.
Price is not an indicator of safety or certification.
Certified eclipse glasses must meet the same ISO 12312-2 standard regardless of cost. What matters is that the seller provides verifiable certification and comes from a trustworthy source.
Pricing can vary depending on several factors:
- Whether the vendor is a direct importer or a reseller
- Each company’s pricing strategy and profit margins
- Packaging, shipping origin, or added customer service
Yes, we include selected Amazon vendors that meet our criteria.
We generally exclude sellers on smaller or less-regulated marketplaces, where it is often difficult to verify company information, stock levels, or certification claims.
Vendors with no stock are removed from our list.
Our goal is to keep the comparison table practical and up to date. Since many suppliers run out of inventory in the weeks before an eclipse, we only display those currently able to fulfil orders.
Spectrum is a direct importer and operates its own sales and distribution channels, which allows it to offer competitive prices.
You can purchase directly through its official websites or at its store in Valencia:
3. Frequently Asked Questions - Safe eclipse viewing
Step 1: Practice indoors, especially with children 👦
- Eclipses are exciting for kids—but safety comes first.
- 👨👩👧👦 If you’re watching with children: practice the steps indoors beforehand, make sure they understand the process, and supervise them at all times.
Step 2: Prepare for Safe Viewing 👁️
- 📖 Read and understand these instructions before going outside.
- 👣 Put on the glasses while looking at the ground—never look at the Sun without proper protection.
- 😎 Hold the glasses firmly against your eyes to block ambient light.
- 👓 If you wear prescription glasses, place the eclipse glasses over them.
- Adjust for a good fit; you can hold them with your hands for extra stability.
⚠️ Important: Never look at the Sun first and then put on the glasses. You must have them on before looking up. This is the most common reason people get eye damage when observing solar eclipses.
Eclipse glasses obscure everything except the Sun. Many people look up, can’t find the Sun, and remove the glasses while still looking upward. Do not do this. Before putting the glasses on—and while looking down—orient yourself toward the Sun so you don’t need to remove them to locate it.
Step 3: Observe the Eclipse Safely 🔭
- Once your glasses are on correctly and you’re oriented toward the Sun, look up.
- 🕒 Observe in short intervals—no more than 2–3 minutes at a time.
- ⬇️ When you want to stop looking, lower your eyes to the ground before removing the glasses.
Step 4: Rest Your Eyes 😴
- After viewing, close your eyes for a few seconds to let them rest.
- 💧 Blink gently or use artificial tears if you feel dryness.
- 🕐 Take frequent breaks and avoid continuous staring to reduce eye strain.
Total solar eclipses:
You must use certified eclipse glasses at all times except during the brief moment of totality—when the Moon completely covers the Sun—at which point you can look directly
without protection.
As soon as the Sun begins to reappear, put your glasses back on.
There are misconceptions about totality: some people believe there are still harmful rays, but this is false.
During totality, the Sun’s bright photosphere is completely blocked, and only the faint corona is visible, whose light is not harmful to the eyes.
Partial and annular eclipses:
You must use eclipse glasses at all times, even at maximum coverage, since part of the Sun
remains visible.
With eclipse glasses that meet the ISO 12312-2 standard, there’s no strict time limit regarding radiation exposure. However, for comfort and safety:
- Take short breaks to rest your eyes.
- Avoid staring continuously for long periods.
NASA warns that “watching the Sun for several minutes straight, even with proper filters, can overheat eye tissues and fluids.”
Yes. Even a tiny exposed fragment of the Sun can cause permanent retinal damage.
The retina’s photosensitive cells (cones and rods) are extremely delicate. During t day, the pupil contracts to limit light, but the Sun’s surface is so bright that even a small fraction can harm your eyes if viewed directly.
Damage can occur even after a quick glance.
- Never look directly at the Sun.
- Always use certified eclipse glasses or proper solar filters.
If you notice any changes in your vision after viewing an eclipse, see an eye care professional
immediately.
Never look at the Sun through a camera, binoculars, or telescope without a solar filter, eve while wearing eclipse glasses. These devices magnify sunlight, can damage the filter, and allow intense light to enter your eyes, causing serious injury.
It is only safe to look at the Sun through these devices if certified solar filters are securely mounted on the front.
