How to Measure the Lenses for Cataract Surgery

People who are suffering from a cataract usually have opaque lenses, which results in a cloudy vision. A person's lens is the densest tissue in the body and very vital in focusing and shaping the things the eyes see. A cataract is a slow progressive condition that involves clouding of the eyes' lenses. If left untreated, this medical condition can lead to blindness. Cataract formation can be caused by several factors such as constant exposure to ultraviolet light, exposure to radiation, age progression, trauma, complication of a disease such as diabetes, and hypertension. It may also be due to a genetic factor. Cataracts may occur on one eye or both eyes. The best solution is to undergo cataract surgery, which replaces the clouded lens with a clear plastic ocular lens. Cataract surgery is usually an outpatient procedure and usually takes only a few minutes. During the surgery, your eye doctor removes the natural lens and replaces it with a new one.

Things You'll Need

• keratometer, IOL (Intra Ocular Lens) Master, or corneal topography device
• Ophthalmoscope or fundus camera
• Mydriatic eye drops

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Instructions

• 1

  Measure the corneal curvature. The cornea contributes to the ability of the eye to focus on an object. The cornea, together with the lens, accounts for two-thirds of the eye's total optical power. If the cornea maintains a strong refractory power, the cornea would need a less powerful lens. Measure the curvature of the anterior surface of the cornea using a keratometer, IOL Master or a corneal topography device. These instruments measures the size of an image reflected from two points on the cornea measuring corneal curvature.

• 2

  Assess for the focal length of the eye. The focal length of the eye is the capability of the eye to focus and defocus light. The eye with the shorter focal length has a greater capability to bend rays more strongly, thus bringing an object to a focus at a shorter distance. To be able to measure the focal length, use an axial eye length biometry ("A-Scan" or "Biometry") that utilizes sound waves to measure the length of the eye and the thickness of structures inside the eye.

• 3

  Examine dilated fundus. Administer mydriatic eye drops into the eye. Common mydriatic drugs include phenylephrine (a specific type is Neo-Synephrine), cyclopentolate (specific types include Cyclogyl and Pentolair), tropicamide (a specific type known as Mydriacyl) and atropine sulfate. Mydriatic eye drops dilate the pupils to get a better view of the eye's fundus. Examine the inner surfaces of the eye using an ophthalmoscope for further abnormalities.