History, How They Work and Where to Buy (2023)

HomeGlassesEyeglass Lenses | Transitions Lenses

By Autumn Sprabary

History, How They Work and Where to Buy (1)

Transitions lenses are brand-name eyeglass lenses that darken with UV exposure and thus provide vision correction and sun protection in one pair of glasses. The adaptive technology of Transitions lenses can accommodate virtually every frame, style, size and prescription.

History of Transitions Optical

In 1940, a research team at Pittsburgh Plate Glass Company (PPG) developed a material called CR-39 monomer. Engineers used the material to line fuel tanks of military bombers in World War II to protect the tanks from bullet impact.

When WWII ended, PPG had large quantities of CR-39 monomer left over, so they had chemists explore other uses for the material. In the mid-1950s, chemists discovered that CR-39 monomer could be used in the production of eyeglass lenses, and it became the world’s most widely used ophthalmic plastic.

A different company, Corning Incorporated, first developed photochromic glass lenses in the 1960s and marketed them under the brand name PhotoGray. Inspired, PPG started testing the photochromic technology on CR-39 monomer lenses.

While another manufacturer called American Optical Corporation beat PPG to the production of plastic photochromic lenses, sales of the lenses did poorly. PPG continued researching, testing and perfecting their product until 1989, when the company marketed the lenses under the Transitions trademark in partnership with Essilor International. The first-generation plastic photochromic lenses were produced in 1991.

In the end, Transitions did not use the CR-39 monomer for the lenses, as they found the material wasn’t suitable for the production process.

The first generation of Transitions lenses needed some improvements, so the company released the second-generation lenses in late 1992 and saw enormous success. Since then, the Transitions brand has produced six subsequent generations of lenses and expanded to a worldwide market.

How Transitions lenses work

Transitions infuses their lenses with trillions of photochromic molecules that change structure when exposed to UV rays. The molecules’ reaction to UV exposure causes the lenses to darken.

Using an exclusive, patented formula, the molecules can sense the level of UV exposure and adjust accordingly.

For example, if you’re in direct sunlight, the Transitions lenses will be at their darkest. Shaded areas or overcast weather will still cause the transition lenses to adjust to the exposure, but will not darken as dramatically as when you’re in full sun.

When transitioning from outdoors to indoors, the molecules will revert to their original state, causing the lenses to lighten and become clear again.

SEE RELATED: How quickly do photochromic lenses transition?

Pros and cons of Transitions lenses

Before investing in a pair of Transitions lenses, it’s wise to weigh the benefits and drawbacks to owning a pair. While Transitions prides itself as the leader in technology for transition lenses, here are some specific pros and cons to using them:


  • UV protection. Transitions offer continuous protection from the sun’s UVA and UVB rays, as well as blue light from your digital screens. So, whether you’re outdoors or in, your Transitions have you covered.

  • Convenient. Many glasses wearers know the struggle of having to switch over from regular glasses to sunglasses. With Transitions, there’s no hassle of juggling two sets of frames, only the seamless adaption of your lenses to your environment.

  • Lower cost. While Transitions aren’t cheap, the investment is less expensive than having to buy a separate pair of prescription sunglasses to supplement your regular eyeglasses. With photochromic eyewear, you’re getting an all-in-one deal that your vision insurance will partially or fully cover.

  • Widely available. If you decide to go through your eye doctor’s office or an optical shop to get your glasses, they’ll likely offer to add Transitions to whatever frames you choose. There are also online vendors that sell transition lenses, but make sure the lenses you’ve selected are Transitions brand lenses before you buy. Many sites sell off-brand photochromic lenses that may not be as effective as Transitions.

  • Easier to keep track of. Having one pair of glasses that will adapt to your lifestyle and environment makes it less likely that you’ll lose them. As long as you remember your glasses, you’ll have remembered your sunglasses too.


  • Cold weather can affect the transition. While Transitions lenses darken when exposed to UV rays, temperature influences how quickly the photochromic molecules react in your lenses. Cold weather causes the molecules to move more slowly, so it may take longer for your lenses to darken.

  • Slow return to clear lenses. Transitions Signature GEN 8 lenses promise to clear up indoors faster than ever. While this may be true, the response is still not immediate. There will be a few minutes during which your lenses will be tinted indoors as they return to normal.

  • Some styles don’t fully darken in vehicles. Car manufacturers typically tint windshields to reduce the amount of UV radiation entering the cabin. With lessened UV exposure, some Transitions lenses may not darken fully while you’re driving. However, the brand has created certain styles (more below) that also darken when exposed to natural light, which addresses this problem.

It’s important to note that Transitions lenses are a specific brand of photochromic lenses, and not all transition lens brands are “created equal.” There are many photochromic lens brands outside of Transitions that have their own set of pros and cons. So it’s best to research those specific brands before purchasing their products.

SEE RELATED: Kodak Lens history and lenses

Transitions lenses colors and styles

With distinct style and color options, there’s a pair of Transitions for everyone. Please note that some color options may be exclusive to a specific Transitions style.

Color options

  • Signature colors. Signature lens colors offered by Transitions include gray, brown and graphite green.

  • Style colors. Transitions lens style colors include emerald, sapphire, amethyst and amber.

  • Style mirrors. Exclusive to Transitions XTRActive, style mirrors provide a slight reflective effect when lenses are clear that intensifies as the lenses darken. Mirror color options include pink, red, blue, green, gold and silver shadow.

Style options

  • Transitions Signature GEN 8. Newest technology from Transitions that gets darker outdoors, has the fastest fade-back time of any lens and is completely clear indoors.

  • Transitions XTRActive. Lenses will sense natural light to darken fully in the car, as well as reduce glare from sunlight and car headlights.

  • Transitions Vantage. Everyday lenses that will both darken and polarize in bright, outdoor light, providing sharper, crisper outdoor vision.

  • Transitions Drivewear. Lenses not only darken, but change color to accommodate light conditions while on the road. The polarized lenses reduce glare to give a clear, picture-perfect drive.

  • Transitions light intelligent shields. The magic of Transitions lenses applied to motorbike helmet shields. Tint color options limited to gray.

  • ACUVUE® Oasys with Transitions. Contact lenses equipped with Transitions technology to soothe the impact of harsh light on the eyes. It’s important to note that these do not replace the need for sunglasses. Non-prescription sunglasses should still be worn when in direct sunlight.

Where to buy Transitions lenses

Ready to equip your eyewear with some Transitions lenses? You can browse in-store or online through the following retailers:


  • Eye care practices. Many, if not all, eye care practices offer their own inventory of frames for patients to browse after their eye exam. Usually, whatever frames you select can be equipped with Transitions lenses. To be sure, call your eye doctor’s office and ask if they offer them. You can also use the “Find Your Transitions” tool on the Transitions website to find a provider in your area.

  • LensCrafters. With many locations from which to choose, LensCrafters offers a wide variety of eyeglass frame brands and styles that they can fit with Transitions lenses. They also offer eye exams, if you’re looking for a one-stop shop.

  • America’s Best. Known for offering exceptional deals on eyeglasses and eye exams, America’s Best will put Transitions lenses in whatever frame style you prefer. Because Transitions lenses are a specialty lens, certain deals offered by America’s Best may not cover them. Speak with an optician if you have any concerns above coverage or cost.


  • EyeBuyDirect. This online retailer has a virtual try-on feature that allows you to see how different frames might look on your face. Once you’ve picked your pair, you can select whether you want Transitions lenses. EyeBuyDirect frequently offers discounts and 2-day shipping on select items.

  • Lensabl. Offering 15% off of your first lens order, Lensabl makes it easy for you to track where you are in the shopping process. The site provides a checklist at the bottom of the page that shows you what steps you’ve completed and what steps you have left before finalizing your order.

  • FramesDirect. If you prefer name brand frames, FramesDirect has them. Show off your Transitions lenses in frames by top brands, such as Ray-Ban, Oakley, Versace and more. The retailer honors a one-for-one initiative, which donates a pair of glasses for every order that ships.

READ MORE: 4 common lens coatings for glasses

Page published on Tuesday, August 24, 2021


What are the 4 types of sources in history? ›

Sources of information or evidence are often categorized as primary, secondary, or tertiary material. These classifications are based on the originality of the material and the proximity of the source or origin.

What are the main sources of history? ›

Primary sources may include diaries, letters, interviews, oral histories, photographs, newspaper articles, government documents, poems, novels, plays, and music. The collection and analysis of primary sources is central to historical research.

What is an example of a primary source of history? ›

Some examples of primary sources are autobiographies and memoirs, letters and correspondence, original documents such as vital records, photographs and recordings, records of an organization, newspaper or magazine articles, journals and diaries, speeches, and artifacts.

What are the two sources of history? ›

Examples of primary sources include: personal journals/diaries/memoirs, letters, court proceedings, legislative debates, newspaper and magazine articles, movies, music, art, etc. Secondary Sources (i.e., historiography) – Books and articles produced by historians.

What are 5 examples of sources of history? ›

Examples of primary sources include diaries, journals, speeches, interviews, letters, memos, photographs, videos, public opinion polls, and government records, among many other things.

What are the 5 types of sources? ›

Types of Sources
  • Scholarly publications (Journals) A scholarly publication contains articles written by experts in a particular field. ...
  • Popular sources (News and Magazines) ...
  • Professional/Trade sources. ...
  • Books / Book Chapters. ...
  • Conference proceedings. ...
  • Government Documents. ...
  • Theses & Dissertations.
May 5, 2022

What are the different types of history? ›

There are six types of history which are political, diplomatic, cultural, intellectual, social, and economic history.

How many sources are there in history? ›

The sources of history are of three types; Material sources , Written sources and Oral sources.In order to find out what happened in the past and how it happened , evidence available from all these sources is collected and thoroughly examined to determine its reliability.

What is evidence in history? ›

Historical evidence is anything directly related to some event, person, or period of the past. It reveals information that might help us better understand what happened previous to our examination.

What is a primary source in US history? ›

According to the American Library Association: "Primary sources are original records created at the time historical events occurred or well after events in the form of memoirs and oral histories.

What is the primary source? ›

A primary source is a first-hand or contemporary account of an event or topic. They are the most direct evidence of a time or event because they were created by people or things that were there at the time or event. These sources have not been modified by interpretation and offer original thought or new information.

How can you classify sources? ›

Sources can be classified in various ways. The most useful classification is by their primary or secondary nature. Another classification is in terms of first-party or second-party.

Why are sources important in history? ›

Documents--diaries, letters, drawings, and memoirs--created by those who participated in or witnessed the events of the past tell us something that even the best-written article or book cannot convey. The use of primary sources exposes students to important historical concepts.

Why is historical sources important? ›

Reasons to Use Historical Sources

Historical sources can be used as evidence to back up your claims of what the past was like. They allow you to say that something happened, whether it's a battle, or the existence of a famous figure. You can then use them to create your own interpretations of the finer details.

What is the secondary source? ›

A secondary source is one that was created later by someone that did not experience firsthand or participate in the events in which the author is writing about. Secondary sources often summarize, interpret, analyze or comment on information found in primary sources. Common examples of secondary sources include: Books.

What are three types of history? ›

There are 6 types of history, and they are:
  • Political history.
  • Diplomatic history.
  • Cultural history.
  • Social history.
  • Economic history.
  • Intellectual history.

What are the 3 types of sources of history? ›

Primary, Secondary and Tertiary Sources.

What is the list of all sources? ›

A bibliography is a listing of all the sources you consulted in writing your research paper.

How do historians write history? ›

Historians who write history emphasize the value of primary sources, that is those sources actually dating from a particular time period, while understanding the limitations of such sources. Non- historians read books or watch documentaries, while historians do that plus go to archives in search of original records.

What are the 10 types of information? ›

Types of information
  • Conceptual information.
  • Empirical information.
  • Procedural information.
  • Stimulatory information.
  • Stimulatory information.
  • Policy information.
  • Directive information.
Apr 17, 2023

Are there 2 types of sources? ›

There are two kinds of sources: primary and secondary. The main difference between a primary and a secondary source is when they were made. In order to determine whether a particular source is a primary or secondary source, you need to discover its time of creation.

What are the 6 concepts of history? ›

The six “historical thinking concepts” are: historical significance, primary source evidence, continuity and change, cause and consequence, historical perspectives and ethical dimensions. Together, these concepts form the basis of historical inquiry.

What are the 4 characteristics of history? ›

  • History is not a list of facts, facts must be interpreted by people. ...
  • History is not about the past- it is about the relationship between the past and the present. ...
  • History is not only what happened, but what did not happen. ...
  • History is not exclusive, but inclusive. ...
  • We must study not only events, but conditions.

How many stages of history are there? ›

The four periods of history are as follows: Ancient Times (600 B.C. to 476 A.D.) The Middle Ages (476 A.D. to 1450 A.D.) Early Modern Era (1450-A.D. to 1750 A.D.)

Where can I find primary sources? ›

For the arts, history, and humanities, original primary source documents usually are housed in museums, archives, restricted library collections, and government offices. Reproductions of primary source documents often can be found in online digital collections, microform collections, books, and other secondary works.

How do you access source of history? ›

You can find published primary sources by using the online catalog, or by searching in a digital collection of historical documents, such as the Gerritsen Collection of Women's History, Chronicling America, and Empire Online. The History Library maintains a list of these collections on its website.

How do we know the past without written evidence? ›

Archaeologists can excavate ancient structures and burial sites and begin to infer how the people lived from fossils (like human remains) and artifacts (human-made items). Archaeologists can estimate the age of fossils and artifacts through several techniques.

What is the first evidence in history? ›

Primary sources are first-hand evidence of history (usually written, but sometimes captured in other mediums) made at the time of an event by a present person. Historians think of those sources as the closest to the origin of the information or idea under study.

Who is the founder of history? ›

Herodotus is undoubtedly the “Father of History.” Born in Halicarnassus in Ionia in the 5th century B.C., he wrote “The Histories.” In this text are found his “inquiries” which later became to modern scholars to mean “facts of history.” He is best known for recounting, very objectively, the Greco-Persian wars of the ...

What is internal criticism? ›

Internal Criticism–this is the process of determining the reliability or accuracy of the information contained in the sources collected. This is done by positive and negative criticism. · Positive criticism refers to assuring that the statements made or the meaning conveyed in the sources are understood.

What is oral source of history? ›

What is Oral History? Oral history is a method of conducting historical research through recorded interviews between a narrator with personal experience of historically significant events and a well-informed interviewer, with the goal of adding to the historical record.

What do historians do with the sources they find? ›

Historians look for sources in the remains of the past, and also from the thoughts of others who have studied the past. They discover new evidence about what has happened and try to interpret the sources to better understand the motives of people and the events that shape our world.

What is secondary in history? ›

Secondary sources are articles, books, and other documents that interpret, summarize, or critique the evidence surrounding a historic event. For example: A book written by a historian is a secondary source.

What are examples of secondary sources in history? ›

Examples of secondary sources include dictionaries, encyclopedias, books, and journal articles.

What is a secondary source example? ›

Examples of secondary sources are scholarly or popular books and journal articles, histories, criticisms, reviews, commentaries, encyclopedias, and textbooks. Secondary sources describe, discuss, interpret, comment upon, analyze, evaluate, summarize, and process primary sources.

How do you identify sources? ›

Evaluating Information in the Research Process: Step 5: Identify Key Sources
  1. Step 1: Do Initial Planning.
  2. Step 2: Choose a Topic.
  3. Step 3: Do Initial Search.
  4. Step 4: Refine Topic / Refine Search.
  5. Step 5: Identify Key Sources.
  6. Step 6: Study Key Sources.
  7. Step 7: Integrate Notes and Ideas.
  8. Step 8: Present Findings.
Apr 5, 2022

What is source information? ›

An information source is a person, thing, or place from which information comes, arises, or is obtained. Information sources can be known as primary or secondary.

What are the three types of information? ›

Generally, there are three basic types of information sources in research including primary, secondary, and tertiary.

What is a purpose of a source? ›

The purpose of a source is the reason it was originally made. The creator of the source put in the time and effort to create it, and it was usually so that it could be used for something. This can be a simple as creating an ancient ceramic pot to store grain.

What is the origin of a source? ›

The origin of the source asks when the source was produced and who by, and the purpose of the source asks why it was produced, and whether it gives a particular message.By including your understanding of NOP in your answers, you demonstrate historical skills which are key to a really well written answer.

What is source analysis? ›

Source Analysis. Analysis is the ability to demonstrate an understanding of the elements that contributed to the creation of a historical source. It answers the question: 'Why does this source exist in its current form?'

What type of source of information comes from a firsthand evidence about an event object person or work of art? ›

A primary source provides direct or firsthand evidence about an event, object, person, or work of art. Primary sources include historical and legal documents, eyewitness accounts, results of experiments, statistical data, pieces of creative writing, audio and video recordings, speeches, and art objects.

What is sometimes called as higher criticism? ›

Historical criticism, also known as the historical-critical method or higher criticism, is a branch of criticism that investigates the origins of ancient texts in order to understand "the world behind the text".

What do you mean by external criticism? ›

External criticism refers to the authenticity of the document. Once a document has been determined to be genuine (external criticism), researchers need to determine if the content is accurate (internal criticism). We conduct historical research for a number of reasons: – to avoid the mistakes of the past.

How are documentary sources further divided into categories? ›

Documentary sources can further be categorised based on their contents and form (or media). Based on the information contents and organisational level these sources can be grouped into: i) Primary, Page 3 9 ii) Secondary, and iii) Tertiary sources of information.

Is a letter a primary source? ›

A primary source is a document - a letter, photograph, diary, manuscript, financial record, book, or even a quotation - that was written or created in the time period you're researching by people who took part in or witnessed the event documented.

What is primary data in research? ›

Primary data refers to the first hand data gathered by the researcher himself. Secondary data means data collected by someone else earlier.

What are the 6 types of sources? ›

In this section you will learn about the following types of information sources:
  • Books.
  • Encyclopedias.
  • Magazines.
  • Databases.
  • Newspapers.
  • Library Catalog.
  • Internet.
Sep 27, 2021

What are primary and secondary sources in history? ›

Primary sources convey first-hand experience of the event or time period you're studying. Secondary sources convey the experiences of others, or “second-hand” information; they often synthesize a collection of primary sources.

What are examples of primary and secondary sources? ›

Examples of primary sources: Diaries, letters, memoirs, autobiographies. Interviews, speeches, oral histories, personal narratives.
Examples of secondary sources:
  • Books.
  • Scholarly journal articles (depends on discipline)
  • Magazine articles.
  • Encyclopedia entries.
  • Reviews.

What are the 3 historical sources? ›

Primary, Secondary and Tertiary Sources.

What are the 5 sources of meaning? ›

Previously, we proposed a strategy that leaders can use to create meaningful work: making the connection to and highlighting the impact their work has on society, customers, the company, team, and individuals' personal success—otherwise known as the five sources of meaning.

How do you cite in an essay? ›

MLA citation style requires that writers cite a source within the text of their essay at the end of the sentence in which the source is used. The parenthetical reference should be inserted after the last quotation mark but before the period at the end of the sentence.

What is the importance of history? ›

Studying history helps us understand how events in the past made things the way they are today. With lessons from the past, we not only learn about ourselves and how we came to be, but also develop the ability to avoid mistakes and create better paths for our societies.

Who collects primary data? ›

Primary data refers to the first hand data gathered by the researcher himself. Secondary data means data collected by someone else earlier. Surveys, observations, experiments, questionnaire, personal interview, etc.

Why is it necessary to determine the source of information? ›

It is important to critically evaluate sources because using credible/reliable sources makes you a more informed writer. Think about unreliable sources as pollutants to your credibility, if you include unreliable sources in your work, your work could lose credibility as a result.

What different ideas can you use in organizing information from secondary sources? ›

You may use the following ideas in organizing information from the secondary sources:
  • LOCATION. -you can organize information by showing visual depiction of a physical space. ...
  • ALPHABET. ...
  • TIME. ...
  • CATEGORY. ...
May 11, 2021


Top Articles
Latest Posts
Article information

Author: Dan Stracke

Last Updated: 04/09/2023

Views: 5955

Rating: 4.2 / 5 (43 voted)

Reviews: 90% of readers found this page helpful

Author information

Name: Dan Stracke

Birthday: 1992-08-25

Address: 2253 Brown Springs, East Alla, OH 38634-0309

Phone: +398735162064

Job: Investor Government Associate

Hobby: Shopping, LARPing, Scrapbooking, Surfing, Slacklining, Dance, Glassblowing

Introduction: My name is Dan Stracke, I am a homely, gleaming, glamorous, inquisitive, homely, gorgeous, light person who loves writing and wants to share my knowledge and understanding with you.