Contact Lens FAQs Answered by Jeremy Sun M.D, Rayme Ophthalmic Clinic

Q1 : How long can you safely wear daily contacts?
A1 : Contacts can be generally worn up to eight to ten hours. Contacts with high Oxygen permeability are proposed for longer wearing period. You should never sleep with contact lenses to prevent from risk of corneal infections.

 
Q2: High water content and high Oxygen permeability are featured in different contact lens brands. Is high water content meant for high Oxygen permeability? 
A2: Hydrogel and silicone hydrogel are two main types of material used to make contact lenses. The hydrogel allows higher water content but wearers’ eyes tend to feel dry when using for long hours. The silicone hydrogel permits higher Oxygen transmissibility to increase comfort of wearing contacts for a long period of time.   

 
Q3 : Why should users follow the wearing period labeled on package of their contacts?
A3: Users should follow the instruction in that contacts with different life span are usually made of different materials.
 
It is important to change contact lenses regularly according to the instructions because of longer wearing time with higher chance of ocular surface inflammation or infection.
 

Q4: Why is Oxygen transmissibility important for contact wearers?
A4: Contact lens reduces the quantity of tears getting on the cornea which receives the nourishment from tears. Contact lens wear can starve the cornea of oxygen and thus Oxygen transmissibility is one of factors to consider when choosing contact lenses.   
 
 
Q5: What is your advice for the first-time contact lens wearers?
A5: Contact lens users should examine their visual acuity, intraocular pressure and refractive power before their first time of wearing contact lenses. Also, a contact lens wearer should follow the use instruction and regularly receive eye examination.
 

 
Q6: How to choose the proper contact lenses from a myriad of options?
A6: Contact lenses should be prescribed by ophthalmologists or optometrists where operate businesses in clinics, hospitals and medical instrument stores. Users should choose products with regulation number issued by authorities such the Ministry of Health and Welfare.
 

Q7: Most users purchase their contact lenses based on their existing lens power. What is your advice?
A7: An annual or half-year appointment for eye examination is proposed to adjust your contact lenses based on the latest vision, refractive power and ocular surface status. Moreover, high myopia defined as refractive power over minus five diopters is at a higher risk of developing ocular complications such as glaucoma, cataract, retinal detachment and age-related macular degeneration. Regular fundus examination is also needed. 
 
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