Why Choose Us?

Professional Team

VisualTech (Shanghai) Corporation, commonly referred to as VisualTech, is a professional supplier of ophthalmic equipment, optometry and ophthalmic medical instruments, as well as optical lab equipment for the eyeglasses.

Wide Range of Products

VisualTech offers a diverse range of products to the ophthalmic industry. Includes combined tables, autorefractor, digital lensmeter, phoropter, visual charts, trial lens sets, trial frames, ophthalmic slit lamp, non-contact tonometer, fundus camera, retinoscope & ophthalmoscope, perimeter, AB scan, Biometer, dry-eye analyzer etc.

Global Shipping

Visua lTech provides comprehensive global coverage, responding to the ever-changing needs of the times. The company has adapted to the transition of traditional offline exhibition models to convenient & efficient online shopping methods. Wherever the need arises, VisualTech is there to provide its superior products and exceptional customer service.

Quality Control

VisualTech is committed to innovative self-development, constantly striving to lead the industry while adhering to the highest standards of quality. The company provides customers with high-quality, innovative and trustworthy services.

How to Conduct the Test: Ophthalmic Slit Lamp

slit-lamp is a low-power microscope combined with a high-intensity light source that can be focused as a thin, slit-like beam.

You will sit in a chair with the instrument placed in front of you. You will be asked to rest your chin and forehead on a support to keep your head steady.
The health care provider will examine your eyes, especially the eyelids, cornea, conjunctiva, sclera, and iris. Often a yellow dye (fluorescein) is used to help examine the cornea and tear layer. The dye is added either by touching a small strip of paper to your eye or by adding it as an eyedrop. The dye rinses out of the eye with tears as you blink.
Drops may be placed in your eyes to widen (dilate) your pupils. The drops take about 15 to 20 minutes to work. The slit-lamp examination is then repeated using another small lens held close to the eye, so the back of the eye can be examined.

What Happens During a Slit Lamp Exam

How Do You Check Eye Pressure with a Slit Lamp

There are many different ways to measure eye pressure. One such method is a painless procedure, called "applanation tonometry." The term applanate means to flatten.
In this test, the eyes are anesthetized with numbing drops. In addition, a small amount of non-toxic dye is placed in the eye. Your ophthalmologist will instruct you to position your head into a device called the slit lamp. Then, a small tip gently touches the surface of the eye and the eye pressure is measured. The eye pressure is measured based on the force required to gently flatten a fixed area of the cornea.
This test can be affected by various conditions, such as when there is too much or too little dye present in the eye, or depending on the thickness or thinness of the cornea. We know that in thin corneas, which can occur naturally or be induced because a patient has had laser correction eye surgery, the eye pressure measured with this device can be artificially low. In addition, naturally thin corneas are an independent risk factor for glaucoma, so measurement of corneal thickness is part of a comprehensive eye exam and should be performed at your initial and/or subsequent visits.

How Long Is a Slit Lamp Exam

How Many Parts Are There in Slit Lamp

The slit lamp comprises two main parts: the illumination arm and the viewing arm. The illumination arm has a light source which goes through a slit beam, and the viewing arm comprises two eyepieces and a biomicroscope.
Both arms of the slit lamp rest on a base. Under the base is the switch to turn the slit lamp on.
The base has a height-adjustable table with its own switch and buttons.
The slit lamp base is on an axle and rails, which enables coarse anterior-posterior and lateral movement. It has a locking screw that must be fully unscrewed in the counterclockwise direction before the slit lamp can be moved.
The joystick can push the entire slit lamp base to attain approximate focus. The joystick can then be gently tilted for fine movements to bring the image into sharp focus.
Turning the joystick clockwise lifts the entire column up, and a counter-clockwise motion brings it down.
The intensity knob (rheostat) is used to adjust the intensity of the light source. The pictured rheostat is in the off position.
The patient's head rests against the support frame: this consists of a forehead rest and a chin rest, the height of which may be adjusted using the adjustment knob.
The canthus indicator is a black line which should be level with the lateral canthus of the patient's eye.
The illumination arm contains the light source; this has an adjustable lever with different filter types. The lever in the far left position is in the "open" position (i.e. unfiltered light).
The beam height can be adjusted via the centre screw. Pictured is a beam height set to 10mm. The cobalt blue light (for fluorescein examination) can be found by rotating the screw counter-clockwise until a click is heard and the dial reads "B".
The beam width can be adjusted via the slit adjustment controls on either side of the base of the illumination arm.
The viewing arm consists of two eyepieces, which may be adjusted for the examiner's interpupillary distance and refractive power. It is generally recommended to keep glasses or contact lenses on and set the power to 0. The magnification control dial is on the side of the biomicroscope.

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