Q. I slip in a reading lens most days in one eye but prefer it out if doing reading for a day. How do you avoid leaving me with that slight negative one gets of a reading lens in one eye?
A.The eye is like a camera. To focus at different distances one needs to change the focal length of the system. In childhood and youth (those wonderful years) the lens is able to achieve this by changing its shape. The lens is made of the similar material as our hair.From the time we are in the womb, lens material gets added every year. Therefore the lens becomes thicker and more rigid and unable to change its shape and hence the focal length. When our hair grows longer we cut it off. Unfortunately no one gave the lens a shave: that is till now when your’s truly will play the role of a barber and shave of the lens using pressure waves;) The non working lens will be replaced by either an accommodating lens or a multifocal lens. These lenses have more than one focal distance allowing one to see far and near.They are made of bio compatible material like acrylic or silicone.
Currently you are using a contact lens to change the focal length. Of course that has its own risks and hassle. Instead an intraocular lens will achieve this. This is NOT like a multifocal contact lens.
Lasik just changes the shape of the cornea and still has only one focal length, whereas PRELEX has more than one focal length