This 15-inch telescope known as "The Great Refractor" was installed at Cambridge in 1847. For 20 years it was the largest telescope in the United States, the most significant American astronomical ...

The all-new OptoChek™ Plus Auto Refractor + Keratometer, part of the VisionChek™ Digital Exam Suite, combines technology with simplicity at the core of your exam. The new, compact, modern design and ...

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If you've decided to get into stargazing and are hunting for the best beginner telescope, you'll first need to decide that type of telescope you're after. If your search to the best telescope for ...

Which refractor telescope is best? Space has intrigued humankind ever since we looked skyward for the first time. While it is difficult to imagine what our ancestors thought of the twinkling lights, ...

The public can now "walk-through" two popular facilities at the Center for Astrophysics. The Center for Astrophysics | Harvard & Smithsonian now offers virtual tours of two popular facilities on ...

AIMS To assess the reliability of the hand held automated refractor Retinomax in measuring astigmatism in non-cycloplegic conditions. To assess the accuracy of Retinomax in diagnosing abnormal ...