Contact Lens
Contact lenses have evolved from blown glass lenses that completely covered the front of the pupil in the 1800s to thin plastic corneal lenses. Today, lens types and materials offer a wide variety of options.
An ophthalmologist performs an eye examination to select the appropriate contact lens for your eye structure. The examination determines the type, degree, base curve, and diameter of the lens to be used. To determine fit, a lens of the same diopter or the closest possible size is inserted. The lens's movement, balance, and centering are examined.
Frequently asked questions?
How to Choose the Right Contact Lenses?
Contact lenses are designed to rest on the cornea. They stay in place by adhering to the tear film that covers the front of the eye and by some pressure from the eyelids.
As you blink, your eyelid slides across the surface of the contact lens, causing it to move slightly in front. This movement allows tears to provide necessary lubrication and helps wash away debris.
As you blink, your eyelid slides across the surface of the contact lens, causing it to move slightly in front. This movement allows tears to provide necessary lubrication and helps wash away debris.
What Should You Pay Attention to When Using Contact Lenses?
The lens that fits the eye is well centered and covers the cornea.
The lens must move slightly to facilitate tear circulation. It should be able to move vertically by 1 mm during the push-up test and after blinking.
The person should see clearly and comfortably and should not feel the lens.
The vision should not change after blinking.
The edge strip should not put pressure on the eyes.
Contact lenses should not be worn while sleeping. They should not be used in the sea or swimming pools.
If you experience redness or a stinging sensation in your eyes while using contact lenses, you should immediately remove the lenses and consult a doctor.
The lens must move slightly to facilitate tear circulation. It should be able to move vertically by 1 mm during the push-up test and after blinking.
The person should see clearly and comfortably and should not feel the lens.
The vision should not change after blinking.
The edge strip should not put pressure on the eyes.
Contact lenses should not be worn while sleeping. They should not be used in the sea or swimming pools.
If you experience redness or a stinging sensation in your eyes while using contact lenses, you should immediately remove the lenses and consult a doctor.
What are the Features of Contact Lenses?
Back surface: The part of the lens that comes into contact with the cornea.
Front surface: The side of the lens that does not come into contact with the cornea. It is curved to change the refraction of light to the extent necessary to correct the refractive error.
Base curve: For a lens to be comfortable, its back surface, which contacts the eye, and the front surface of the cornea must be compatible and have a similar curvature. The base curve is the radius of the optical area of the back surface. Because it is the curvature that determines the fit of the lens to the eye, it is one of the most important parameters. If the lens is too tight, the base curve should be enlarged; otherwise, it should be reduced.
Front surface: The side of the lens that does not come into contact with the cornea. It is curved to change the refraction of light to the extent necessary to correct the refractive error.
Base curve: For a lens to be comfortable, its back surface, which contacts the eye, and the front surface of the cornea must be compatible and have a similar curvature. The base curve is the radius of the optical area of the back surface. Because it is the curvature that determines the fit of the lens to the eye, it is one of the most important parameters. If the lens is too tight, the base curve should be enlarged; otherwise, it should be reduced.