Nidek Lensmeter LM-500

Dispensing opticians use the LM-500 to establish the powers present in a patient's spectacles and assess lenses during dispensing. Sphere, cylinder, and axis remain visible while the frame sits on the table. The holder secures the selected lens at the nosepiece, and the displayed right-or-left designation keeps each result associated with its side. Existing spectacles can therefore be described through their measured optical properties.

Progressive-lens work gives the directional display a particular role. An operator follows the transition from the distance zone to the reading area while the instrument tracks local power changes. Near-position indicators support the final horizontal and vertical adjustments. With automatic capture selected, the system retains a stable result at the aligned position. This suits dispensing and verification tasks where a measurement's location matters as much as its numerical value.

Optical laboratory staff use the marking assembly to transfer a chosen position and orientation to an uncut lens. The three-dot line provides a physical reference for subsequent handling in the workshop. Sphere, cylinder, and prism remain available during positioning so the marks relate to the selected optical centre or prescribed prism point. The optional foot switch supports capture while both hands remain occupied with the lenses.

Within an optometry service, the contact-lens nosepiece extends the same bench station to support contact lenses. Dedicated display fields include spherical equivalent alongside sphere, cylinder and axis. Bifocal and trifocal work uses separate segment readings to preserve the relationship between distance and addition. Configured computer or NIDEK instrument links carry measured results forward, allowing the dispensing station to add lens information to the broader examination record.

Visible direction through progressive zones

The alignment display gives the operator a movement cue as powers change across the progressive area. Its arrows, target and near-position indicators connect the measured region with the next physical adjustment. This makes the distance-to-near sequence explicit: the lens moves by hand, the sensor follows the local power pattern, and the screen identifies the aligned position for capture.

Lens values remain associated with the correct side.

Right and left result areas provide a structured view of a pair of spectacles. When automatic side selection is enabled for the relevant spectacle sequence, the designation advances after the stored reading and lens removal. This creates a clear link between the handled lens and its displayed values, with manual side selection available through the function buttons.

Three reference dots carry alignment into workshop handling.

The measured position has a physical output via the cartridge marker. Its three points establish a line parallel to the lens table, preserving the chosen centre and axis orientation on the lens surface. That relationship helps when an uncut lens moves from optical measurement to the next workshop stage, because the positional reference stays with the lens.

Supported lens types share a single bench station.

The instrument supportsinstrument supports single-vision spectacles, segmented multifocals, progressive lenses, and contact lenses through dedicated routines. A nosepiece change enables contact-lens support, and the display switches to the corresponding result layout. Dispensing and laboratory teams can organise these measurement tasks around one set of controls, while retaining the appropriate capture method for each lens type.

Power notation adapts to the optical task.

Cylinder results can appear in positive, negative or mixed notation, and prism can be expressed in polar or rectangular coordinates. These choices change how the measured optical quantities are presented. The same station can therefore support a prescription expressed as sphere, cylinder and axis or a prism task expressed through base directions, with the result format visible on screen.

Compact body leaves room for lens handling.

A 180 mm width and 185 mm depth define the instrument's tabletop footprint. The front-mounted nosepiece, table and controls place the measuring area directly below the display. This arrangement supports a dedicated dispensing position where the operator can bring a frame onto the support, read its values and apply reference marks within the same working area.

Connected output links measurement with the next record

Results can leave the instrument through its serial or USB connection in a configured system. NIDEK identifies compatible instruments that receive lens data and provide communication printing. A computer connection uses the required driver and communication software, while the Eye Care card system is an optional data-transfer route. The output arrangement can therefore follow the station's already specified receiving equipment.

Optional foot control keeps capture close to the handling task

The OPFS-3 foot switch provides an alternative trigger for reading measured data. In workshop sequences where both hands support the lenses, the pedal allows capture without reaching for the read button. The button stays active when the switch is connected, so the operator can use the capture control that fits the current positioning task.

Routine upkeep focuses on accessible optical and marking parts.

The protective glass sits beneath the removable nosepiece, making optical-path cleaning a defined part of regular upkeep. Replace ink cartridges when their marks become faint, using separate white, red, and blue references to identify the consumables. These two maintenance areas support the instrument's central jobs: reading light through the lens and leaving visible positional dots on its surface.

108-point Hartmann sensing

A Hartmann sensor evaluates 108 positions in the nosepiece region simultaneously. The arrangement detects local variations in refractive power relevant when a progressive lens moves between viewing zones. Its sampling area is tied to the supported measurement position, allowing the display to respond to the optical region currently above the nosepiece.

535 nm measuring source and selectable reference conventions

The 535 nm green light supplies the measurement beam. Result presentation can use the e-line reference at 546.07 nm or the d-line reference at 587.56 nm. These are separate optical quantities: the source wavelength identifies the light the sensor uses, while the selected convention identifies the wavelength basis for the reported power.

Spectacle sphere and cylinder measurement

Spectacle sphere spans -25.00 to +25.00 D, and cylinder magnitude extends to 10.00 D. The instrument offers positive, negative and mixed cylinder notation, with axis from 0 to 180°. The sphere and cylinder fields use selectable 0.01, 0.06, 0.12 or 0.25 D increments, while the axis field advances in 1° steps.

Separate addition fields for segmented lenses

Add and Ad2 preserve two addition values for supported multifocal sequences, each within the 0.00 to +10.00 D range. This supports the intermediate and near segments of a trifocal lens after establishing its distance reference. A near-sphere display option shows a segment as a single sphere value, preserving the relationship between the distance power and the measured addition.

Prism magnitude and base-direction views

The prism range reaches 15.00 prism dioptres, with 0.01, 0.06, 0.12 and 0.25 prism-dioptre display steps. Polar presentation pairs magnitude with a base angle. Rectangular presentation separates base-in or base-out from base-up or base-down, keeping horizontal and vertical components available during positioning and marking of a prescribed prism location.

Automatic progressive recognition and directional guidance

In automatic measurement mode, a detected progressive power variation changes the display to its progressive layout. The distance and near routines then use targets and arrows to indicate lens movement. Near-position indicators add directional information for final alignment, making the progression from one viewing zone to the next visible throughout the hand-positioned measurement.

Selectable automatic and button-controlled capture

Automatic-read settings retain a result when the selected alignment and stability conditions are achieved. Separate settings govern the distance and near stages of progressive measurement. The read button provides a direct capture control, including for contact-lens and segmented-addition readings. You can also select the right or left display to follow the configured spectacle sequence or choose it via the buttons.

Dedicated contact-lens nosepiece and equivalent-power display

The supplied contact-lens nosepiece supports lenses larger than its 5 mm inner opening. Contact-lens sphere spans -25.00 to +25.00 D under the specified 6.00–9.00 base-curve condition. The dedicated screen shows spherical equivalent, sphere, cylinder, and axis; spherical equivalent combines sphere with half the cylinder value.

Lens-size and transmission conditions

Spectacle lenses from 20 to 100 mm in diameter fall within the stated handling range. The optical measurement accepts transmission of at least 10%, increasing to at least 20% for spherical powers with magnitudes of 15–25 D. These conditions describe the lenses presented to the measurement system, and contact lenses use their separate nosepiece diameter condition.

High-index material compensation

An adjustable Abbe number from 20 to 60 represents lens-material dispersion, the way refractive behaviour varies with wavelength. Three stored selections retain the corresponding value for different materials. A configured computer connection can also supply the Abbe setting. This compensation function accompanies the instrument's selectable optical reference convention.

3.5-inch colour LCD and physical function buttons

The full-graphic colour display has a 320 × 240-dot layout and shows measured values next to the alignment target. Icons identify the functions assigned to the physical buttons beneath the screen. A contrast control adjusts visibility, and the display can enter an automatic-off state after a selected idle period, with the measuring light switching off alongside it.

Lens table, holder and cartridge marker

A movable table supports the lower edge of a spectacle frame while the holder maintains lens contact with the nosepiece. The marking lever applies a three-point reference line parallel to the table. NIDEK identifies the cartridge marker for repellent-coated lens surfaces, with replacement white, red and blue cartridges supporting continued marking work.

Fast measurement refresh

The minimum measurement time specification is 0.09 seconds, with a ±10% tolerance. During positioning, the display updates measurements, and the read function retains the chosen value. This timing describes the measurement update; the working sequence also includes lens placement, alignment, segment selection and result capture.

RS-232C and USB computer communication

One RS-232C port and one USB port provide the instrument's wired data connections. NIDEK identifies USB 1.1 communication with a computer through the appropriate cable, driver and communication software. Serial arrangements support specified NIDEK refraction equipment and the optional Eye Care card reader/writer, keeping the result destination dependent on the configured receiving system.

Communication printing through connected equipment

NIDEK identifies compatible AR and ARK instruments, including supported handheld arrangements, and TONOREF II as routes for printing measured lens data. The receiving instrument supplies the printer within that connection. The lensmeter's export controls initiate the configured data transfer, allowing measured spectacle information to accompany other results at the receiving station.

Defined supply and optional controls

The original loose accessories comprise one power cord, one dust cover, one contact-lens nosepiece, one user guide and one progressive-lens explanation sheet. Optional items include serial and USB cables, the OPFS-3 foot switch and the EyeCa-RW reader/writer with Eye Care cards. Marking-cartridge replacements support the integrated marker, with part references distinguishing their ink colours.

Mains-powered tabletop construction

The 3.5 kg body operates from 100–240 V AC at 50/60 Hz, with ±10% voltage tolerances at the specified endpoints. Its rated apparent power is 40 VA, and it uses a Class I protective-earth connection. For electrical protection, the stated operating environment is indoors at 10–35°C, 30–85% non-condensing humidity and 800–1060 hPa.

The LM-500 suits dispensing teams and optical workshops that handle progressive lenses by hand and value visible guidance through their changing powers. It shines at the measurement station, where directional cues, selected capture settings, and a physical marking reference keep the result tied to the lens being handled. Contact-lens work has a dedicated support and screen, while configured data links extend the station into an existing record workflow. Routine care centres on a clear optical path and legible cartridge marks. For this work pattern, the instrument combines guided power measurement and reference marking, with 108 sensing points in the nosepiece.