Isis eyepiece from Vision Engineering gives a wider view.

Many microscope users know all too well that prolonged use can be a real pain. Many systems demand that the user maintains a rigid body posture which can become increasingly uncomfortable, and concentrating on the magnified image for long periods can lead to eye fatigue and nausea. It can all add up to a serious reduction in accuracy and efficiency in the short term, and a long-term risk of debilitating repetitive strain injury (RSI).

Many manufacturers now design their microscopes to be ergonomically efficient, making operation as simple and intuitive as possible while minimizing the risk of strain or fatigue. Leica Microsystems of Wetzlar in Germany, for example, worked with the Fraunhofer Institute of Stuttgart, Germany, to design its DM series of microscopes. The main control panels are positioned for direct and intuitive access, and height, viewing angle and eyepiece length can be adjusted to suit the user.

The narrow field of view from most microscope eyepieces is a major cause of eye strain and bad posture. Users who wear spectacles often have to remove them, increasing the risk of eye strain; and many users also suffer the distraction of floating fragments of tissue debris in the eye.

Vision Engineering of Woking, UK, a company specializing in microscope ergonomics, claims to have solved these problems with an eyepiece called the Isis expanded-pupil system. Fitted in place of the traditional eyepiece, the Isis is based on a small disc containing more than 2 million microlenses. This disc rotates at about 5,000 r.p.m., so that the millions of individual optical paths are merged to form a single high-clarity image, with an exit field around ten times as wide as from a conventional eyepiece.

“The key thing is the image, and where the image leaves the microscope and meets the operator,” says international marketing manager Geoff Collins. “Our technology allows the image to have a much wider exit pupil, which means you can see it from much further away, from a greater range of angles. That allows you to move your head around, wear spectacles, and be further away from the eyepiece.” Isis is available on Vision's own range of laboratory microscopes, and as an accessory to replace the conventional eyepieces on a wide range of commercial microscopes.

T.C.