Difference between conventional and disposable contact lenses
Conventional Disposables
Advantages Disadvantages
Variety of curvature available. Easy to find a perfect eye-fit. Standard range of curvature available. Harder to find a perfect eye-fit.
Wide degree-range. (especially for astigmatism). Limited degree range.
Lenses are made of non water-friendly materials, does not attract oily secretion, therefore, will not dry up so easily. Lenses are made of water-friendly materials, attracts oily secretion, therefore, dry up easily.
Lenses are lathe-cut. High in accuracy. Lenses are mass-produced. ( Lower in accuracy as compared to conventional).
Lenses can last for a long period of time, at affordable price level. Lenses contain high water content, easily torn.
Lenses are in form, easier to wear and take off. Suitable for beginners. Lenses easily go out of shape, harder to wear and take off. Suitable for skillful wearers.
Disadvantages Advantages
A protein layer may be formed after wearing for a period of time, may lead to allergies or even infections. Lenses are frequently being disposed, little chance for protein layers to be accumulated.
The lenses is usually thicker, takes a while to get used to. The lenses is usually thinner, offers high level of comfort.
Lenses need delicate handling. Lenses can be disposed frequently and need not delicate handling.
No back-ups or replacements are available immediately when the lenses are damaged. Immediate replacements are available when lenses are damaged.
•  ?a TIP to digest?
•  Exercise your eyes by blinking:
  1. Place your finger on the end of the eye brow, pull back the muscle towards the ear.
  2. Start blinking the eye with the same force exerted to pull back the muscle. (Repeat 20 times)
  3. Continue for 2 weeks, practice 3 times daily.
•  Remember
  ĦE Cleanliness is the basic rule to wearing CONS!
  ĦE Wash and dry hands before wearing or taking off.
  ĦE Go for regular check-ups

ĦE Beginners should go for check-ups on the first week and the first month after wearing. Skillful wearers should go for check-ups once every half a year

•  What will affect the performance of wearing contact lenses?

Name of illness



Solution and prevention

Conjunctival Hyperamia

Blood vessels around the conjunctival turn intense red and become thick.

*irritants from the surroundings entered the eye.

*eyes became dry.

*allergic to the disinfection solution.

*unsuitable curvature of the lenses.

If the suggested symptoms continue, go for a check-up with the optometrist to find out the actual cause.

Papillary Conjunctivitis

Discomfort may not be observed at first, however, secretion will increase, thus lens repulsion may occur. It may worsen to become 'Giant Papillary Conjunctivitis' when not treated properly.

Insufficient cleansing left dirt lingering on the lenses. The dirt attract germs to start breeding, which will cause irritation to the conjunctival.

PS: This type of illness is especially common among people with nose allergies.

Cleanse and disinfect the lenses every time after wearing. Also remember to dispose and change lenses on time!

Epithelial Straining

In minor cases, eyes will become dry and the person may experience 'foreign body sensation'. For more serious cases, the person will experience blur vision and stinking.

*broken lenses.

*unsuitable curvature.

*irritants or dust have entered the eye.

*allergic to certain preservation.

*rubbing the eyes excessively.

STOP wearing contact lenses immediately and go straight to the optometrist for a check-up!

P.S: For minor cases, the cornean has self-recovery ability to heal itself within 24 hours, however, in serious cases, scars may remain for life-long!

Stromal Oedema

Stromal Oedema even happens to non-wearers, if they sleep for too long a period of time. In serious cases, the person will experience blurring of vision.

*lenses worn for a long period of time without resting

*curvature is unfit for the eyes

*wore lenses while sleeping

WARNING! Lenses should not be worn continuously for more than 12 hours! (take off your lenses as soon as possible when you reach home)This is to allow breathing time for the cornea.

Corneal Neovascularisation

Does not have any noticeable symptoms, the person will feel neither itchy nor painful in the eyes. Can only be discovered through a slit lamp biomicroscopy test.

When there is an accumulation of dirt on the lenses, or when curvature is too tight for the eyes, or when one wore contacts continuously for a long period of time, it decreases the oxygen permeability of the blood vessels around the cornea, hence, causing the blood vessels to extend growth into the cornea for oxygen.

There is no cure for 'Corneal Neovascularisation' as the in-growth of the blood vessels cannot be undone. Once the vessels reach the pupil margin, it can lead to blockage of vision or even blindness. Therefore, it is essential for regular check-ups with the optometrist.